Since the biggest winners of an independent Biafra would be France, China, Rhodesia and South Africa, I'd imagine that the latter two would try to engage in some insurgency efforts to divide communist groups if they try to take over Mozambique/Angola.
Eritrea might try to pull off an earlier independence, using the unpopularity of Haile Selassie as well as any aid from Libya to pull it off.
Britain might be forced to accept the possibility of secessionism. Wilson/Heath would have to put out fire after fire if they wanted to defy the inevitable.