It is always possible to renegotiate commitments made in a WTO agreement, whether it's plurilateral or multilateral. However, we must not forget that the member states consider it a privilege to be part of the WTO. Its members are in an exclusive club. When you withdraw privileges from a trading partner, the WTO expects you to negotiate with them and compensate them if the withdrawal or change in commitments costs them money. So it isn't easy.
On April 15th, 2021. See this statement in context.