I'm new to Phalaenopsis orchids.
I bought this one about one month or two ago, and when I got home and repotted it, I noticed that 90% of its roots were rotten.
I still pulled through it and now I'm in the process of saving it.
It looks better from day to day, and formed new healthy roots, and so far, it's looking fine. At least compared to how it looked in the beginning.
A week ago it started forming this small knob on the remaining flower spike I left, and now, I'm wondering, if thats just new flowers forming, or if it's a Keiki, a new baby plant that will separate from it's mother soon and can begin living on their own?
Is this a sign of severe stress ("I'll die soon, this is my last resort!") or does it tell me "Thanks for not throwing me into the trash, here's a small gift for you!"?
Whole plant: 
The "thing" one week ago: 
First visible air roots forming, a few weeks ago:
The plant when I got it:
Hard to tell, I've had Phalaenopsi put out more flowers on old spikes, as well as babies. We've had one for over 10 years that's been through quite a bit before I finally pulled it out of the moss we bought it in, cut most of its roots out, and potted it in bark.
In my experience, they're pretty hardy. I would personally let the spike go until you know what it is and make the call. Watch the leaves, as long as they don't get more raisney I would probably just leave it alone.
I think the "raisiny"-effect on the leaves is just because of dehydration. Remember, the roots were pretty much non-existing up until now.
But I think it will recover :)
Absolutely. If the leaves don't perk up I would snip the flower/baby spike.