Re-signed Tom how & with what money?
Tom's last contract was signed in June of 2019. It was a 2 year contract with almost all of the money as bonus money i.e. guaranteed. Included in that contract was a stipulation that he could not be franchised and that the second year of this contract voided at the end of the season, which occurred on March 1, 2020.
Note: A player cannot renegotiate or extend their contract for one year - in this case June of 2020, which a quick glance at a calendar would show that this date is after March 1, 2020. Therefore, they couldn't renegotiate it before it voided.
Next note: once the season ended and his contract voided, Brady's remaining bonus money, $13.5 Million, immediately converted to dead money. Any contract he signed would be in addition to that $13.5 Million.
Last note: Brady immediately began discussions with several teams - not the Patriots - and less than 3 weeks later (March 20), signed with the Bucs for $25 Million for 2 years with incentives (all earned in 2020 BTW, making his 2021 salary cap number $27.5 Million). He did not give the Patriots the opportunity to match it because they couldn't, even if they pulled Thuney's $14 Million Franchise tender. They were up against the cap (this was pre-COVID opt-outs) and Thuney's $14 Million wasn't enough to sign Brady for a $38.5 Million ($25M + $13.5M) cap hit.
Brady was gone the minute the ink dried on that last contract and there was nothing the Patriots could have done to stop it.