I could well see Dana remaining even if the UFC are bought out, perhaps even retaining all or part of his own interest in the company with a new investor just buying the Fertitta's out. He is obviously part of the image of the company although I spose you could argue his value has declined in more recent years.
I do think it makes sense to potentially sell now, Ronda and McGregor have brought the company to a high point that its uncertain it will remain at in the near future.
As far as what it could mean I would be hopeful a new owner takes a more long term view. Personally I'v always thought the Fertitta's treated the UFC post TUF as too much of a cash cow to help prop up Station Casinos taking too much out and thus damaging the future of the sport. Right now things still look pretty rosey as were dealing with a talent base that was established before the near UFC monopoly but I don't think ne wtalent is coming close to replacing the talent were likely to lose in the next 2-3 years(especially with no TRT and tighter testing).
The good thing with MMA is that I think investment in talent can give you results much more quickly, most sports your talking 5-10 years before investment in youth training comes though but in MMA your talking more about investing in fighters to switch sports. The UFC for example could probably go out and flash the cash right now and have half a dozen or more world class kickboxers switch, many of whome have already dabbled in MMA training.