Bruce, all the Buffalo stations are still here, just some have moved around. You probably need to re-scan.

ION (virtual 51) broadcasts on RF 24 moving there last summer, also moving from a tower in Pavilion, NY (Genesee County) to a tower in Wyoming County formally used by Virtual 49. Ch 49 moved to RF 16 on Grand Island for a short time.

From information I have been able to find but not verify, after only a few months, RF 16 started being used for ATSC 3 broadcasting by virtual channels 2, 4, 7, 29 and 49.

What I do know is virtual 49 is now scattered across the other stations in the ATSC test:
49-1 on RF 32 (ch 29)
49-2 on RF 34 (ch 7)
49-3 on RF 33 (ch 2)
49-4 on RF 36 (ch 4)

Re-scanning your tuner will pick these up providing you can receive all the RF channels.