Is it possible for the bitcoin difficulty to reduce? I thought difficulty always increases after each halving.
Pool miners will continue mining no matter what.
of course it is. there've been plenty of times when difficulty has fallen. it's not related to the halving, the same amount of coins arrive no matter what the difficulty is. the mining algorithm is designed to be flexible and responsive.
and whether someone continues to mine depends on their circumstances. some miners take the long view, others might not survive a few weeks in the red.