That (tendency to appear during NDEs etc) might be a lot to do Don with the fact that (if I've got it right) traditional Christians are the only ones (?) who have actually deified their teacher, made him an independently existing singular and immortal God.
I'm not sure about what Islam teaches (but they seem to quite clearly separate and distinguish between God and the Prophet) but is it not the case that they see Muhummad as having been an enlightened human teacher of one sort or another?.
I've never heard anything that leads me to think that Buddhists would expect to somehow meet the Buddha - they conceive of him as having been just one of many emanations of the true nature of mind (albeit one of a very few who having reached his level incarnated in a physical body) who in the form he lived is long dead. He's not (at this level of a single being) seen as having been an immortal God or anything like that.
The very many emanations (check here for one listing
http://www.buddhanature.com/#adi) correspond to the multiple aspects of (ultimately the only) mind there is. All can help us in working with our own mind.
Bear in mind as well that that principle (Buddha nature) is seen as not just a higher principle but as the ultimate nature of all of us. Go within and this is ultimately what you find. But you also find yourself.....