while we are facing attacks, miners, please don't leave until the HF, on the contrary : put the maximum hashpower so foreign hashrate will gain less and when HF comes, the first block will be easier to mine.
I'd say the first block after the HF will be the hardest to mine

Suddenly only CPU/GPU miners hashing but relatively high difficulty from the few ASICs which mine IRD now and to the HF.
Will take a few very slow blocks until difficulty drops to where it should be.
Imagine we still had the original very slow DAA or even the one that BTC has. The chain would remain stuck forever with those, if a few ASICs would drive the difficulty sky high before HF.