I think a new Deus Ex game is inevitable, but you really think they'd remaster the older titles? I'd pay double for a decent remaster of the original DX.
(I'll just write "Embracer" to avoid having to sort which publisher calls the shots in this case.)
It would make a lot of sense. A new Deus Ex would probably be made by the studio which made HR and MD, simply because they were very good games. Safe bet, low risk, yadda yadda.
But the Montreal studio is busy with one or more unannounced game(s). It's more likely they are working on something Marvel related than a new Deus Ex. Unless we're getting lucky and it's already in the works, it could take another 2-3 years before development even starts. So there could be a time window of 5-6 years available to do something with the older games.
A quick tech-fix remaster for the first 2 games, with minimal work apart from that, would probably be a small project for one of their specialized studios. Or for a bigger studio between projects.
Black Forest Games for example worked on at least one smaller remaster (Titan Quest for consoles) and a port (Risen 3 for PS4) before they did the Destroy all Humans Remakes. So Embracer likes to shuffle things around and stay flexible.
The business reasons are obvious. At least the small remasters are dirt cheap, and ports based on it probably too. So that's easy money, given Embracer's expertise on very broad monetization of their back catalog. Bigger remakes are a different beast, but still less risky than a new IP.
Even here Embracer tends to be flexible. The Black Forest GM said in their DevPlay (*) YouTube show that the original idea was to do the quick turnaround tech thing for DoH. But they managed to convince their publisher to let them do a full remake including all assets except voices and music. The math worked and the project made money. They're working on the sequel.
Now Embracer has precise numbers to decide if there's a market for a new game and how big the budget can be.
There's a problem Embracer needs to solve though, for all games coming out of the new studios they bought from Square Enix: They are console studios. The Dutch studio (**) which made the superb PC conversions for the last couple of Tomb Raider and Deus Ex games is no longer available. So the know how needs to be found elsewhere.
The good news is that we can expect a lot of high quality ports of Playstation exclusives from Sony.
(*) German language, with Black Forest Games, Piranha Bytes, Deck 13, King Art and the guys who did Fantasy General 2, plus guests.
(**) Nixxes handled the PC ports for more or less all relevant EIDOS North America games since the year 2000.