From what I understand in this part, you will not lose the coins and there's a workaround, but I don't really understand the process.
No, there is no workaround. Read what I said again:
Since segwit has already activated, such a fork would result in you losing any and all money that is in a segwit output, both nested and native.
What I described later is how miners would actually spend the segwit outputs to steal your money. There is no workaround to not have your money stolen after such a hard fork. The only thing you can do is sent all of your coins to non-segwit outputs before the fork happens.
Well, that kinda sucks to be honest. On that case, I will be sure to keep my long term storage coins in the original bitcoin format, and use segwit for transacting, but not storing the coins (and I will still use the classic format for transacting if the fees aren't too high)
In the case a hardfork, what would happen to your BTC if the BTC are held in a lightning network hub/channel thing? You would also lose them so you need to move them back to a legacy format address?