Surely it was only a matter of time. CX has been unusually generous to lower tiers compared to any other carrier, with priority check-in and boarding for GR and lounge access for SL.
Before everyone gets too worked up, a couple points: If you're SL, you're not necessarily at an airport that often in the grand scheme of things. If they're going to give out vouchers (which already is more generous than other oneworld programs at the ruby level) you may well be covered for many of your airport visits. And if you're a SL at 50,000 club miles, say, then some changes they appear to be considering could be to your benefit, including a rollover if that's really on the table. OP, did the survey suggest they're thinking of adding tier bonuses? If so, that would be worthwhile compensation for losing the lounge benefit.