Absolutely zero motivation from his agent to do that. Makes sense from the teams pov though.
Connor Hellebuyck had a three year ELC and then signed a one year deal. Just like Swayman.
When that contract expired, Hellebuyck had been a Vezina runner up, and has started over 60 games twice and 50 games once. Much more proven than Swayman.
He signed a 6x6.2 deal which is about a 6x6.8 deal in today's dollars.
Juuse Saros signed a 3x1.5 deal coming out of his ELC. Coming out of that deal he was 26 (one year older than Swayman). He had never started more than 40 games (although that was in a 56 game season in which he came in 6th in the Vezina voting). He signed a 4x5m deal under a 81.5m cap (around 5.4m AAV today).
Shesterkin signed a 4x5.6 deal coming out of his ELC. He had one year of being the starter under his belt and everyone knew he was the best up and coming goalie on the planet.
Swayman finished 7th in the Vezina last year (only starting 44 of 82 games) with a very good two rounds in the playoffs.
I think its fair to say he has an equal or worse resume than those guys did when they signed their deals.
The Bruins want 8 years, but they probably won't get it, but I think your reasoning is very poor given that every other agent here did a deal in the 4-6 year range as the compromise with only Helly getting in the 6-7 AAV range by giving up 4 UFA years.