Assuming that AAZA intend to continue with the Sun Bear program in the longer term. I think one of the keys to future success is going to be working closely with the European breeding program for them.
The Sun Bear EEP had been through a rough period of several years with no births for nearly 10 years and very few transfers among the existing population. However a new studbook co-ordinator took over in 2018 and following several much needed transfers, 5 births (to four pairs) have taken place in recent times.
There is also two new EEP holders coming on board (one of which has already received 1.1 and the other will receive Bears once the new enclosure is finished later this year) which opens up further opportunities for breeding.
Overall the current EAZA population is looking a lot more positive than it was 5 years ago. There's still a serious female bias (All 5 of the recent births have been female's) but at least they are breeding on the plus side.
My longer term hope would be that eventually the EAZA population becomes stable enough that an agreement can be formed with AAZA and Sun Bear transfers between the two regions become possible.
Importing pairs or individual rescued/Orphan Bears from Sanctuary's in Asia has it's place, and I don't doubt this important initiative will and should carry on. However if the AAZA population is going to continue long term then they need to be looking for mother raised, well socialized bears who are more likely to successfully breed.