Epistemic status: former geopolitical analyst focused on East Africa (for 2 years), but haven’t kept myself much informed in the last 4 years and haven’t read anything about the East Africa Federation.
I would have very little hope in this (estimate: < 1% chance of a federation with all of these countries being formed in the coming 25 years). Many (all?) of these countries have disputes of power along ethnic lines, so the idea of relinquishing power towards a supranational government seems very unlikely to me. E.g., South Sudan can barely form a government for its own country, so the idea of joining a federation seems hopeless.
I would find it more relevant to simply foster economic growth among the East Africa Community, or to work on improving governance within each of these countries (except perhaps Rwanda, which instead can work on securing good governance once President Kagame leaves power).
Happy to further detail my views or discuss this in more depth with anyone interested :)