It is significant because it was being leaked at the time that there was "bombshell" after "bombshell" that Trump had colluded with Russia and/or been compromised by them. This and the litany of other texts in the briefing show that they had basically zero evidence of this ever, that many were on a partisan vendetta against him, and were using dubious tactics (such as these NSLs) to generate "evidence" or at least the appearance of evidence.
I dont think Trumps tweet had anything to do with him colluding with Russia. The Steele Dossier hadn't even been leaked at that point. I'm not sure what in any text makes you think confirms there was zero evidence of anything. These are texts from unidentified agents and we don't even know there involvement in the investigations. Have you ever worked at large organization (or small)? If some coworker says, "I think Ted is only pushing this project because he wants to make trips to Miami for the strippers", is that evidence that Ted is going to Miami for strippers?