As long as they were suitably enjoyable and rewarding.
I'd also be curious if SOTA would work better in that format, I remember when it was originally released, demolishers in it were much slower - not the turbo-charged monsters they are today that end the game in seconds if your team doesn't bother to slow / snare them. It'd require some speed-win achievement retooling, but I think it'd work much better if it was a slower game type, though maybe that'd clash with wintergrasp a bit - at the moment the cannons are pointless though, feels lackluster.
I do think IOC and AV need something done though, splitting them is the first step towards allowing that.