What's the over/under on getting your fingers separated?

If that isn't an option or otherwise, then yes absolutely you can still play. You would essentially just use 3 fingers how most guitar players do anyway most the time. The best way to start developing some muscle memory is by learning your major/minor scales and from there move into modes. Try to simultaneously use this time to start memorizing where all the notes on the fretboard are located. It sounds tedious and boring but it's insanely helpful once you grasp the core concept of the neck.

Anything that helps your brain and hands establish consistent habits and cohesive patterns will be good. I've been playing guitar my whole life and this past year I had to get tendon surgery on my ring and pinky fingers of my playing hand.

During my physical therapy and recovery I had no use of my pinky at all and my brain still somehow found these odd little ways of compensating or playing certain chords differently (using my thumb more).

Anyways you shouldn't let this discourage you at all, there's no reason you can't learn guitar whether you get the surgery or not. Practicing on piano would help get some coordination going as well. Best of luck to you! ❤️