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:
Looks like a flower spike to me though I'm no expert. If you want to learn more about orchids I would recommend the YouTube channel "miss orchid girl".
I would also think this a flower stalk