Tigray has gotten the experience of going it alone during the last 2 years, namely, since Amharu blocked all roads coming from Ethiopia through Amhara kilil. Thus It is easier to secede now than 2 years ago. Meshrefet blocked Tigray from getting its share of all the loans and aides Ethiopia gets from international donors and has cut most of Tigray's share of the so-called federal budgetary "dugoma" and is giving it to Oromia and Amhara Kilils on top of their share.
BTW: Tigray produce several times more electric energy than it consumes.