That's an important point: a lot of 5E players weren't even born in 2008.I can only comment on my experience. But I didn't, at that time, encounter any players who were determined that they would play 4e and nothing else.
It is, of course, entirely possible that if I'd stuck with 3.0e then my players may have rejected that. It just wasn't a problem I encountered.
As regards the 2014/2024 split, we don't actually know yet what will happen. Maybe the 2024 release will be so obviously superior that everyone converts. Maybe it will be a damp squib and nobody much converts. Most likely, it will be somewhere in between. But one thing that's unique about this version change (and hasn't been true since the very first) is that for the vast majority of the player base this is their very first version change. Which means that the old "rules" about how it will go don't apply any more. We'll just need to wait and see.