F16s have better radars, amongst other things, so will be able to see further, which means the Russian air force will have to launch their weapons from further away. This means 1) more time for them to be intercepted and 2) what the Russians can hit is somewhat decreased. I'm sure our resident radar expert can correct/expand on this.
Additionally, for the past 12 months or so the Ukrainian forces have been concentrating on neutralising Russian air defences, my assumption is to increase the safety of the F16s when they arrive, thereby giving them more flexibility and give them a greater impact.
SEAD (Suppression of Enemy Air Defences) is one of the most dangerous jobs for a pilot, but essential for air superiority. The fact that much of it has already been done by ground forces makes things much easier for any air operations.
What remains to be seen is how good Ukraine can be at combined arms fighting ( coordinating ground and air forces); this is something NATO spends a good chunk of its time practising as it is so difficult to do well. That said, Ukraine has been doing it for a while and one of their (IMO main) strengths thus far has been the ability to quickly learn from their experiences. Russia is also learning, but nowhere near as quickly as Ukraine.