That's true. Caro in the eyes of some people has SS light years ahead of others. The same people name Maria S' skating juniorish. I do see some difference but not that big difference speaking about this year programs. And I think Kostornaya's SS are just superb.
More like Sochi-Caro has SS light years ahead of any of these current top ladies. Caro this season is significantly slower with less complicated footwork.
As for Maria Sotskova, when compared to a true junior, let's say Alena Kostornaia since you've mentioned her, Maria has significantly less transitions and ice coverage and way more crossovers / two-footed skating in her program.
When watching their performance in the (Junior) Grand Prix Final, what I noticed was Alena uses occasional crossovers to gain speed and most of her performance was completed by one-footed skating with decent speed and fluidity. The entries and exits to her elements tend to be packed with transitions.
(Example here)
Maria, on the other hand, has a skating dominated by crossovers and adds in one-footed skating and turns occasionally. Given the footwork is simpler, her speed is comparable to that of Alena. Note her crossovers after technical elements: Alena requires no more than three crossovers
(Example here) to regain speed while Maria often requires 5-6.
(Example here) Also, the entries and exits of her elements are mostly crossovers.
(Example here) It is very obvious that she has skating skills inferior to that of Alena Kostornaia, a true junior, so I would rather not call Maria's skating "juniorish" as that would be an insult to what the top junior ladies have shown us what they are capable of.
Undoubtedly, Maria Sotskova has improved her skating skills from last season, which (in her FS) started off with posing around the logo for 15s, crossover around the rink for 15s, jump, more crossovers, repeat. However, she still has a lot of room for improvement.
ETA: I've never compared the performance by these two ladies side-by-side. The comparison is striking. Alena scored 0.61 points more than Maria in TES in (J)GPF, despite having one less element (ChSq), and she is clearly superior in SS, TR, PE and IN. The Russian Fed better have a good reason if Alena does not get a score she deserves in the Russian Nationals this coming week.