EZETTIE LATUASV IVAKMHA
I've just reached this and, since nobody has answered, I will now.
Yes, he is.
There are actually 3 of them. Wiktor Witkowski is the eldest, then Miłosz, and then Kornel.
I can't find any results for Wiktor from the past 5 years, so I take it he has retired. The younger two were in Dundee for the Tayside Trophy a couple of weeks ago. And they finished like this in the Free Skate:
But, Kornel had a big advantage from the SP, so he finished 7th, with Miłosz in 9th.
Nothing like a bit of sibling rivalry to spice things up.