Why make two of the same IP that compete against or diminish each other, they could do the reboot taxi and have an ace classic mode for old fans using the same assets and stuff rather than produce two full new titles, especially if they add gaas-like stuff to the remake like cosmetics/multiplayer.
You don't 'add Gaas' if you want to seriously compete in the space - there are ground-up design choices that require significant up-front investment, or you just spend a lot of time/$ rebuilding the game later (Which does happen too, tbh).
If you want a very concrete example - R* spent more money on building the
launch version of GTA:O (that's
excluding all the costs of the core GTA5 game) than most AAAs get for the full game. And that's an example where base assets are largely identical between the two games.
Now all that aside - I did always think CT lends itself very well to a MMO-lite experience and it could be very successful as a GaaS (possibly more so than the base game ever was, across all its iterations). But (and that's a big but) it will require people that actually know what they're doing - hopefully this isn't being asked from teams that only built regular console games - we've had a wave of burned studios back in early 2010s on exactly the same GaaS gold-rush, we don't need another one of those.
What's weird is this makes it sound like there will be two versions, a traditional stand alone and the GaaS. I think it's risky for them to launch those a different times, in the event that the traditional game gets overlooked it might make it hard to get the service game started.
It might be a case of hedging bets - eg. if remake is basically just original game reskinned with Nanite assets - while the service will be built from ground up with more modern mechanics. It's certainly a case where building the GaaS version is likely to take longer (possibly substantially so) so it could also be an idea to build brand awareness with the remake, in lead-up to launch of the service - but to your point, that could also backfire.
I am more curious about what the hell JSR GaaS reboot would be like. I mean I can sort of picture it like some gang-wars style competing for territories etc. - but would people really want to spray-paint competitively?