In a development that has not received wide publicity, Chairman Bennie Thompson has requested (backed up by subpoena power) phone register records for hundreds of people in relation to their activities on January 6, including Members of Congress…
These records will confirm a few things.
who contacted who and when, and for how long, and text messages may be recoverable, though the contents of the phone calls will likely not be known.
One thing to note, is that this step would not have been taken unless the FBI signed off on it, as it could compromise criminal investigations.