VTI is market cap free-float weighted, as is VOO and SPY. So what ETFs would this IPO be an issue with if not these?

So far only the Nasdaq-100 has gone along with SpaceX's special weighting chicanery. The biggest fund which tracks the Nasdaq-100 is QQQ. Suffice to say, if you have money in QQQ you should be re-considering that position.