I am not sure whether you have problems with comprehension, or where the problems is, but you completely missed the point. Let's explain it again:
I am not saying that Lena and Ruslan were sitting around doing nothing, they were obviously skating together, but at the same time they were waiting what will be the news from Sinitsina/Katsalapov. They did not know whether their old partners will come back or whether this is not permanent move. (I am not saying they were praying for the partners to come back, but common sense would probably win over their feelings). So that would make them approach the Federation much later than Sinitsina/Katsalapov who actually knew that they are not coming back. While Lena and Ruslan were waiting for Sinitsina/Katsalapov to make up their mind, Sinitsina/Katsalapov approached the Federation and requested to be recognised as a new couple. The Federation announced them. As soon as Lena and Ruslan found out that this is it, they approached the Federation and the Federation announced them too. The Russian Federation could not announce Lena and Ruslan BEFORE Lena and Ruslan approached the Federation, and Lena and Ruslan did not approach the Federation earlier because they did not know what the outcome of the S/K's trial will be.
In regards to your question why would be Nikita the first one and the only one to decide, well, Elena was willing to skate with him, and he was not willing to skate with her. That gave him the power. (No, it is not fair, but it all depended on his decision whether he will skate with her or not).
After Nikita and Vika run away without real explanation, both
Lena and Ruslan were repeatedly showing that they want to be approved like new couple...
….around 7th of April both Lena and Ruslan announced that they will skate together
…15th of April the head coach Stifunin was invited at practise, he promised to give good recommendations in front of Russian Fed
…a journalist Vaitsekhovskaya was invited to come at practise to see a new couple
…a photographer is invited to make a photoshoots from practise
…23th of May Ilia Averbukh says that he is already working with Lena and Ruslan and prepare new FD…
Hanca, if you are not sure about new dance partner, you are not behaving like that. No skater prepares new competitive programs and invites specialists and journalists at practise while he/she is not sure who he/she WANTS to skate with. I can accept the idea that two dancers without partners are skating together and trying steps and compulsory dances not to forget how skating with partner looks like. But in moments when competive programs and all round showing to specialists start – it is visible that Lena & Ruslan wanted to skate together, not to wait if their partners will change their minds…
And let’s look at Russian Fed behaviour…
…in moment when Lena and Ruslan announced that they will skate together in 7th of April – Piseev was almost rude to Ruslan saying that Ruslan’s private wishes doesn’t speak about anything…
…11th of April Gorshkov announced that Nikita and Vika did an official request to skate together, but he (Gorshkov) wants to let them skate, let them try together and then the decision will be done, he gives them THREE WEEKS
…Zueva changes three weeks to four weeks…
…22th of April Gorshkov says that decision about Lena’s partner will be done in months probably, he says that changing partners is a difficult process, it needs time to try and see if things go well…
It is strange that while head coach Stifunin saw the couple 15th of May and he liked the couple and promised to tell Russian Fed only positive things, one week later Gorshkov still looks like that time for try-out is needed? Why, when Lena & Ruslan were looking OK? In my opinion he was waiting for Nikita, because nobody from Russian Federation saw him with Vika, and Russian Fed was probably hoped (in very naive way), that Nikita will come back to Lena, so Gorshkov didn’t even mention that Lena and Ruslan will be a new couple…
And look at Nikita…
…around 4th of April he says to Lena that he will no longer skate with her
…11th of April he and Vika made an official request for becoming new couple
…13th of April Zueva announces that the couple is coming to her for try-out
…since that time once a week Zueva sings a romantic songs about S&K – their perspectives, their beauty, their speed, their eyes
…16th of April media announces new couple – S&K
…since 28th of May all Vika, Zueva and Nikita speaks in superlatives about themselves
In which moment could Russian Fed have any idea that Nikita may change his opinion? So why should Lena & Ruslan couldn’t be allowed by Fed to skate together like new couple after head coach saw them and liked them? Why they had to wait until Zueva and Fed were sure that Nikita can some way skate with Vika?
Uhh mentioned that no couple was officially confirmed (signed documents about funding probably), OK, but S&K were announced like new couple 19th of May, so even before 31th of May. Why I&Z couldn’t be announced in press after head coach saw them? Why they were finally announced 4th of June, which was 4 days after deadline?