Even if bitmain has something new coming, it's not going to affect ROI as much as difficulty increases. With all the new miners coming online in March and later this year, difficulty is going to the moon while BTC price is stagnating. I already see it in my mining. Anyone buying S9s now at $2320 may never break even anymore. Especially if difficulty doubles every 3 months like it did the last 3 months.
I hear you. But I guess a lot of that depends on the electricity cost too. Also posts like yours make me hesitant to buy more s9s, but at the same time people have been saying not to mine for a long time, but the people who have been doing it over the last 5 years have made an absolute killing.