I don't think the f-16 will make that much of a difference. In fact, I think less than other wunderwaffe's as RU does have pretty robust air denial against aircraft targets.
The wunderwaffe's Ukraine have had so far include drones, Javalin, NLAWs, HIMARS,ACTAMS, Patriot, Storm Shadow Leopard 2 , M1 Tanks... sure they did make a impact to Russian operations when they were first introduced, but I really suspect they are running out without replacement. Once the kill ratio's between UKR and Ru draw closer... I suspect something will collapse and the parties will come to the negation table.
As much as we people laugh at Russian Arm's production, its probably in a better shape than the what the EU can do.