Cannondale's introduction of BB30a, which is incompatible with regular BB30 cranksets just means that in the future it's very likely that BB30 cranksets will have longer spindles. With spacers, they will work with an BB30 BB, so there's no worry about "future proofing". Also there are many adapters that allow for use of Shimano cranks and others, in many ways a BB30 bottom bracket is very broadly compatible with all cranks currently available, and I would guess, will remain so for a long time.
On the other hand, my experience with BB30 and pressfit BBs in general has lead me to avoid them in future, I didn't like having to get my BB replaced 3 times in a year (the third time when I did it myself and locitited it, does seem to have held up OK). But there are many on here that will tell you that BB30 problems are entirely the fault of the installer, others who will tell you it's a fundamentally flawed system.