That's up to what the project requires. You'll need to remove the refrigerant either way.

if removal would require some roof work, and they plan to remove the roof next year, you could leave them up till then. Just an example and you or the owner need to make a decision. I usually just prefer to remove it all and don't leave a mess for later. But my example would convince me to leave it for next year instead of hiring a roofer now, and next year again.

As EnergyProfessional pointed out, it is up to what the owner/tenant agree beforehand.
For instance, in our property at our retail spaces, we require the previous tenant to remove all their stuff and leave the space in shell and core before handover.
we still didn't have a situation where the tenant remained the same but changed space purpose. In that case, I believe that we would accept that the tenant leave some of the stuff, providing that it was cleared by the time the lease was up.

Only thing I’d add to these answers is if you don’t remove the outdoor unit at least label it as abandoned and what it used to do. In a building with a lot of condensers this can sometimes be a big help to us poor engineers trying to trace out tiny refrigerant piping.

Best practice is definitely to remove them and patch the roof. If you're really pinching pennies the cost you get from scrapping them will cover some or all of the cost of the roof patch (depending on what the roof assembly looks like) but worst case you'll get a little offset.

By removing them and making the roof repair now, you eliminate the potential for abandoned units which aren't being maintained in any way creating roof leaks or other problems later.