I'm sure I'm not alone here, but the Eternal Masters release doesn't have any personal effect on me whatsoever.
In basically every instance, I have the cards I need to play, but even if I didn't, I would never choose to obtain the version being printed in Eternal Masters. Not only will mostly every classic reprint come with a new and unidentifiable illustration, but they will also be printed with the new frame, new font, and snazzy hologram. No thanks.
With all of that said, however, I'm still sincerely excited to see what Eternal Masters brings to the table: for my own curiosity, an overall historical intrigue, and to hopefully help out players still looking to pick up essential cards. The question I wonder, though, is whether Eternal Masters will actually be a real help for people to obtain desirable cards such as (potentially) Karakas or Mana Drain.
In all likelihood, Wizards of the Coast will probably make the mistake of upgrading the rarity on nearly every critical card. I've written about this before in great detail, but I still feel like it wasn't tasteful to upgrade the rarity of cards like Dark Confidant, Vendilion Clique, and Tarmogoyf. Combine this issue with the small print run and overpriced MSRP. None of this is helping the players. I'll give Wizards of the Coast some credit, though; I was pleasantly surprised to see Wasteland printed at rare and not mythic rare. That's a great call; a real "for the players" action. With Wasteland being a Vintage, Legacy, and Commander staple, it's a card that most players need to own.
They will probably assume Force of Will, Wasteland, and Imperial Recruiter will be enough to sell packs and put garbage in the rest of it.
I agree. On the back of Force of Will and Wasteland alone, Wizards of the Coast probably figures that those inclusions are more than sufficient enough to sell a ludicrous amount of booster packs. I don't disagree. With Force of Will and Wasteland in the set, I assume that it'll become less likely that players will see the addition of other top tier cards such as Imperial Seal, Mana Drain, and Mana Crypt this time around.
Even still, how much has Modern Masters really helped with the supply of staple cards? It'd be silly to say that sets like this haven't helped at all, but at the same time, the cards are still very rare and, if I recall correctly, prices didn't drop much. If a price dipped, it was often due to playability and relevance, not due to scarcity becoming a non-issue. I'm sure there is some real data out there that proves how Modern Masters helped or didn't help with card pricing, but I'm just speaking from a casual perspective.
I don't think that sets like this really do enough to help the overall player base, but I think that they certainly do something. Either way, I am hopeful that Eternal Masters will create more opportunities for players to own important cards, and most importantly, help to create new interest in paper Vintage.