That info is relevant because it links the same actors in the timeline he has before him.
The legitimacy of the information is for Freedom Watch to present to Nunes.
Nunes asked for any person having any knowledge related to the committee’s investigation to come forward. Klayman has come forward.
Timeline is not the issue as Clapper and Brennan were actors in all the timelines of concern. If they were illegally conducting surveillance then, they were likely conducting surveillance more recently. Nunes does not need to let them off on a technicality.
If Nunes ignores it, Klayman will file in federal court. That will undoubtedly force Nunes to bring Montgomery in for questioning, followed by Clapper, Brennan and any under them carrying out their instructions. The hearing with those parties will grow a life of its own. It will detonate in some fashion.