Well, now they have the Polish Army plus a US tripwire.
Putin has no intentions re Poland (he is, after all, a realist). So the F-16's are just for show...unless Obama is stupid enough to order them into Ukrainian airspace.
Putin knows the Poles would kick his ass.
I don’t think Putin is ready to take on Poland. However, what is now Poland was actually part of the former Russian Empire 100 years ago or so, and Putin has intimated he’d like to re-establish that empire, at least territorially, so let’s keep an eye on this.