I'd actually prefer that the subsidies - tax credits are still a subsidy - be phased out entirely. As Trump said in his speech, the best way to expand coverage is to make it less expensive. I'm hoping there was some significance to someone inserting that line into his speech.
I truly believe that allowing a truly free healthcare market will make insurance cheaper. Make insurance cheaper and you don't need the subsidies. I'm not saying we pull the rug out from everyone who is currently getting a subsidy, but I'd prefer them to be phased out.