I'm not even convinced he really means it yet. Easy to imagine him watching what happened on Saturday night, the farce and drama of it all, and getting the buzz back briefly, but it's a different story once he's actually training properly again and at least vaguely living the life. I hope winning the belts back really does motivate him as much as getting them in the first place did, because if this is just an impulsive move the comeback won't end well. Be great to have even a 75% Fury back in the mix this year though.
Plus, as mentioned above, he is still suspended from fighting in the UK, think his hearing is in April, so they're either reasonably confident in the outcome or this is over before it begins.