Nasdaq, Inc. is a company with a stock market ("the NASDAQ") and an index "Nasdaq 100"). They want SpaceX to be listed on their market, because they like having more things on their market for all the usual reasons. They are, apparently, offering to manipulate their index to win the listing.
Accordingly, anything that uses or tracks this particular index (Nasdaq 100), such as the QQQ fund, will potentially have to pay for this manipulation.
Anybody not holding or indexing to the Nasdaq 100 index contents will not particularly care and will not really gain or lose any more money than on an ordinary trading day. In particular, this will have zero effect on stocks that merely trade on the NASDAQ exchange.
Indexing to the Nasdaq 100 is pretty uncommon, outside of QQQ, so most people will not care.
The index is just a function of the stocks. It only moves if the underlying stocks move. Rebalancing Nasdaq will cause selling in the 100 companies that aren’t SpaceX. And those stocks are held elsewhere too…
The Nasdaq 100 shares 79/100 stocks with the S&P. So if those stocks move (probably down because they’re being sold so SpaceX can get bought) pretty sure that's gonna affect anyone exposed to those companies. Whether that’s directly or through other index ETFs. Many of which have a huge concentration in Mag7 right now, for example.