I would expect a reduction in range, but only by a modest ratio, not like orders of magnitude. The common mode emission is annoying, and makes a CMC just about mandatory; but they're commonly found, anyway, so that's probably a non-issue.
CAN was derived from RS-485; there's been 3.3V RS-485 transmitters for a long time. The original RS-485 transmitters were implemented in TTL, which only delivers about 3.5V tops, which LVCMOS easily matches.
Tim