There's probably no problem there Doc. While i've never heard a Buddhist teaching to the effect that we can remain in the non-physical in some sort of teaching role (it doesn't remotely mean there isn't one), it seems likely to follow logically from the principle that we are inevitably driven by our deepest beliefs and convictions.
'Dissolution' too just happens to be the word used in some quarters for a process which (while we're maybe not quite sure of the detail) we're pretty sure happens.
Reincarnation is likewise by the principle that beliefs/attachments determine outcomes presumably only inevitable for those (very much the majority) attached to continued physical existence in the earth life system. (that's almost Monroe speak
)
It seems perfectly reasonable that there may be some who while they are not ready to transcend individuality are more than ready to give up earth life to enable them to maximise their assistance to others. There may also be others who while they could move on choose to remain in this sort of teaching role - in much the same way that Buddhism teaches (the Bodhisattva ideal) that realised teachers have chosen to be reborn on earth for this same reason. By what we have said there may even be some early on acting out the facade of teacher, and misleading others...
It's maybe worth saying too that Buddhism posits that there are many realms into which we can be reborn, and many of these seem not to be physical, or at least do not seem to operate to the same rules as earth life. (the wheel of life briefly sketches some of the possibilities)
It does teach though that a human life (better still an appropriate one) is pretty ideal as a basis for spiritual progress - tough enough to force us to confront the reality of egoistic behaviours, but not so tough that we are driven out of all consuming fear into karmically unhelpful behaviours - which could in turn cause re-incarnation in an even worse realm.
The result is that it's taught that we should do all the spiritual work we can in this life to help ourselves gain the freedom from ego needed to enable an optimum (suitable human) re-birth. (it's basically taught too that we should not over indulge in this sort of speculation
- that we should instead concentrate on our knitting. That is work at what is directly relevant to our spiritual progress)
There's a pretty high degree of unanimity between spiritual teachings too to the effect that we (even those realised) ultimately don't gain complete freedom to move on until we collectively transcend individuality. (i can't say if 'we' means just all humans, or all earth life, or as i suspect it may mean all physical and non physical life with any attachment to individuality in the cosmos. Buddhism routinely talks of assisting 'all sentient beings')
What i can't even speculate on is what the full range of afterlife possibilities may be - but i can't help feeling too that the possibilities are probably infinite.
You mention choice, but i think it's not a simple matter in this context. We all have 100% freedom of choice at all times, and indeed there exists the possibility of our deciding to move beyond this sort of existence at any time.
The problem is that out of fear we actually are unable to bring ourselves to do so - the attachment to physical existence, self-hood or whatever other ego inspired beliefs we hold, and the fear caused by the possibility of losing what we as a result mistakenly value (by the principle above) binds us to the possibility of only those options we can entertain.
When dominated 100% by unthinking, instinctive and reactive ego backed by a rigid template of associated beliefs we presumably have no freedom of choice at all, whereas those who have developed rather more equanimity have freedom within the areas they have ironed out.
The realised person can access this total freedom of choice, but i think maybe that at that stage the love we all hold for our fellow beings (but which is significantly obscured by ego in most of us) kicks in and we become unwilling to move on without doing what is necessary to release them too. We all become Christ....
Pardon my going on, but it's quite scary and at the same time wonderful territory....