Once these guys -- all first- and second-year pros -- are tendered offers, they can't even negotiate with other teams. So you can look at them as invitations to return to the team.
Anyway, as you might've seen earlier, ERFAs Gary Guyton and Bret Lockett were both extended tenders to do just that next year, with each pulling down offers somewhere between $400,000 and $500,000. Things with another ERFA, RB Chris Taylor, didn't look so rosy as the deadline approached, and it appears he will not be tendered an offer from the team.
Guyton, of course, was a starter last year for New England, while Lockett played on special teams. Taylor went on IR before the season.