Hard to say. My understanding is that publishers are most concerned about the early sales of their games, and want to secure especially (but not necessarily only) them with DRM. Not only against full time pirates and sk€n€-d00dz who probably can get the cracked version out fast, but even the most casualiest(?) gamers who might share their brand new game bought from the local store with all their friends, if there was no DRM whatsoever to stop them. I think this is also the reason the publishers seem to be so keen nowadays to make second-hand games less valuable, or even useless.

That in mind, I personally do not think GoG will be able to muster that many new-ish titles, if they remain completely DRM-free. I guess it would be fine either way to me: either GoG releases only years old games DRM-free (like now), or releases also newer DRM-games that are guaranteed to become DRM-free at some point (or otherwise they would not be sold in GoG to begin with).

The problem with the current situation is that since GoG will miss the sales of new titles completely (and they appear on Steam, GG, D2D etc. instead, with DRM), there may be less and less incentive for the publishers to re-publish the games again on GoG, thinking people can get them from the other services if they want.

From my point of view, it means many game compilations etc. may remain incomplete on GoG, possibly forever. For example the Stronghold series, or yesterday's hidden gem promo, the Alien Shooter series. The other sites are able to offer the whole series even as a special pack, while GoG can offer only a part of it, a couple of older titles in the series. That's the reason I'm holding off buying e.g. the Stronghold games from GoG, just so that in the end I don't end up buying the same games several times from different services through special promo packs, compilations etc.