I doubt ARM would have survived long without being separated from Acorn, Few companies would use a processor whose fate rest with a competitor. This is one of the things that killed DEC's Alpha processor (it was practically only used by DEC, so when DEC folded, there were no users anymore). Though we can dream of Acorn holding on to ARM and sweeping the competition away by using a vastly superior processor, this is not really a realistic scenario.
The lack of licensing was one of the things that prevented first BBC-clones and later Archimedes clones from expanding Acorn's systems into a wider market. And if ARM wasn't made more accessible, the same would have happened to it.