We do need to see more. He can also earn that paycheck by blitzing up the middle, something he has been good at while stunting from OLB.
However, if Wilde is to be trusted (and he isn't usually Captain XandO) then previously Matthews was a WILL in a 4-3 alignment (Quad). So his current job is different as a ILB in a 3-4 (I assume he is likely to play ILB in base).