Are you familiar with how Ghidra works? You run it own your own computer on a binary that you feed it. It’s not like it talks to the NSA to exfiltrate things.
He's not completely wrong though, you do want to be careful when your using something developed by someone like the NSA. It's the same reason you want to be careful using cracked versions of IDA since the guys that can crack IDA can probably do other stuff to it.
I think thats part of the reason NSA open sourced the code for it so people could see no backdoor are in there. So in this particular case maybe less of a concern
