Abiy Ahmed has his own reason for not wanting to fulfil his Pretoria obligation and thereby not return Western Tigray. This is often overlooked by focusing just on the Amhara expansionists themselves but it shouldn't.
It's known by most now that Amhara expansionists want Western Tigray due to expansionism, profit and to harm Tigray. What is not discussed nearly enough is that Abiy has his own separate (However not completely because Amhara expansionists contradictorily also share this reason) ideological reason for not wanting Western Tigray returned. He wants to undermine multinational federalism and eventually dismantle it in order to fully centralize his power. What happened to Western Tigray being legitimized is the first step in such a process. PP have already explicitly shared their desire to undermine/dismantle multinational federalism (1) and we've already seen all that they've committed and said since gaining power in 2018.
I recommend that you watch Daniel Berhane's discussion on Addis Standard because he speaks in depth on this (part 1, part 2).
This explains why Abiy hasn't taken the steps that would've been the most strategic from his pov, if not for his broader goal, as some have been rightly puzzled on. Abiy respecting Pretoria and thereby returning Western Tigray would've severed any connection between Eritrean and Amhara forces and would've prevented the alleged strategic alliance that was formed between TPLF and Eritrea. Abiy prefers to push for all his goals no matter the risk even if it means antagonizing/fighting everyone else and that will be his undoing.
You can also read through the following for more context:
The following posts on the post pretoria/current period: (1,2,3,4,5,6)
Social media/podcasts on Tigray
Common anti-Tigrayan arguments being debunked - The section on multinational federalism is especially relevant.
Posted Feb 18, 2026, 10:02 AM UTC