not all altcoins will die. maybe history like 2017 will repeat itself. right now I think big altcoins might like ethereum, xrp and others will still be able to survive if altcoin is priced at $ 100k but altcoin with low prices, low volume and also less interested. will definitely fall
Altcoin will loss its value and it's possible. You must not take the old history of the altcoin as a good information to determine where will the market be going on as so many experts have been doing the same and they are all getting failed to predict where is the direction of the market.
And it is very hard to happen what happened in 2017 and i agree with you that altcoins will not die right away when bitcoin's price reached $100,000, those altcoins who have no potential and good future will slowly loses its value and honeslty i think most of altcoins will slowly die if ever bitcoin reaches $100,000 and for those good altcoins out in the market tha will survive will surely have a massive price increase same aa bitcoin.