Knowing now that the rules will be in less expensive books makes me less concerned with the $50 price tag of the PHB. Especially if they are books that, when I'm done running them, I may had out to a player or two who cannot or will not pay $50 for a PHB.
How do we know that the rules will be in less expensive books?
Good question. I'm going on the price of the sword coast adventure. If tyranny follows a similar model the PDF will be much cheaper than 50$ and contain next rules. Not all of them but maybe enough of them.
Well when a new edition is coming out of course people are going to be talking about it.
Doesn't mean they are going to play it though.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.