What makes you think there’s a plan to upgrade?
The fact they aren't resigning him is a fair indication.
Although, this could be his decision, in which case there's nothing we can do about it.
Players like to test the market. He probably has an offer from us and wants to see if he can beat it. Which is what I would do too if I was an aging LB on possibly my last opportunity to get paid.
But it's not something fans should be crying about. I'd be fine if he stayed, it's one less position to worry about, but at the same time he's a bang average player and bad in coverage.
It's not a terrible FA class to let him test the market. Dre Greenlaw, Devin Bush, Ernest Jones and Zach Baun are all upgrades, but guys like Tyrel Dodson, EJ Speed, Robert Spillane and Jamien Sherwood are either a wash or a slight upgrade.
My personal preference would be Devin Bush. Top 10 pick, had a good rookie season, then tore his ACL and never got back, went to the Brown's this year and had a great season on a poor defense. Looked back to himself.
Despite a good season as a unit there's not a player on this defense that can't be upgraded outside of Budda.