Is 80-90 degrees celsius hot for MBP 2019 CPU temperature
Solution 1:
I just checked mine, a 2020 16" MBP i5 with 16 GB of RAM and it's running at 83 degrees celsius. So I would say yes, this is normal. I am currently running a Time Machine backup and the fans are running.
You can check the temperature of the CPU die from the Terminal via the sudo powermetrics | grep -i "CPU die temperature" command. You will need to kill this with a Control-C command.