I think we can get a bit too fixated on 1st, 2nd, 3rd, 4th lines when speculating new/returning players pre-season. One thing we can absolutely no for sure is that with Thompson if you play well, you go up the lines and increase your ice time. If you’re not up to speed, your place is not so certain the following week.
Speculating Brandt on a particular line, as a fixed place which may hinder chances on coming back is not accurate, the way I see it. If Brandt is on fire again, he’ll be top line - and I think he’ll know that now after the great form he showed last season and how he was rewarded by Thompson for that run of form.
BTW, I’m fully aware lines are a big consideration particularly when mapping out team balance and configuring left/right handed players etc. Just that players continually fluctuate up and down the lines for a variety of positive and negative reasons.