To address some of this trade speculation, I would think that he would've signed the tender sooner. My common sense says, if you are going to a new team, you would want to do it sooner rather than later.
Personally, I feel like the franchise tag needs some refinement. It's purpose is for a team to retain the rights to a player and pay an average salary of the top 5 players at that position. That's great, but what it should do in the end is eliminate deadlines, etc. for that specific contract negotiation. Meaning, while contracts/extensions can't be discussed after a certain point in the offseason, the franchise tag would give you the option to extend talks with that player.