I don't quite know what you're expecting anyone to tell you. 10% reduction in traffic means "there will be 10% fewer flights in and out of affected airports during the cutback." Whether that means "more 100% full flights" or "more 100% full flights and people start getting bumped more" is up to each individual airline and on how overbooked they allow themselves to get. It's sometimes plausible for an airline to swap in higher-capacity aircraft for super-busy routes, and they'd rather upgrade somebody to first class for free (or cheap) than leave a seat empty anyway if they overbook coach, so it really does come down to each airline's policies.
If you're worried about in-air changes, they always prioritize landings over takeoffs, so once you're off the ground, your flight's in good shape.
Arrive early for your flights. Upgrade if possible (any kind of upgrade will do -- even just "earlier boarding" in coach will make your seat much more secure assuming you're there to sit in it at the earliest opportunity). Be friendly, polite and patient with the gate staff. Like, literally offer to go pick up some fucking coffee for them when you check in and poke fun with them at any other passengers openly being assholes. I'm not even kidding; if you make a positive impression with them early on, yours will the last seat they'll consider bumping for someone else if it comes down to it.
