You raise a very good point, and I can't even start to guess at the answer or implications.
I think any data the NSA has would be stringently guarded and only used for high-profile / high-impact cases. If the NSA was constantly feeding data to other agencies about trivialities, then it would raise red flags about where "all this incriminating evidence" came from.
Cases involving StingRay interceptions have been dropped so as to protect the details of such interceptions.
There's also the relationship between the agency and the Government to consider. The CIA don't seem to get along very well with various members of the US Government, and with "good" members such as Ron Wyden, if the NSA was feeding ill-gotten data to the US Govt, then someone like him would probably raise some kind of stink.
This doesn't answer the fundamental question of whether the NSA has this data, it's more about the potential mitigation of the likelihood of the data being actually used against someone.
Much like we don't know where the line is on the potential for Huawei kit to be a threat to national security.
Something. Not nothing.
Edited to add:
There's also the very likely situation where Government policy / regulation is put in place to cover all parties, and the NSA ignores this anyway because they're above the law. Everyone else must play by the rules, the US Govt looks to be doing the right thing.
(this isn't a bitter statement, merely that I think this is how things actually work, whether for the US or any other country; realpolitik)