What I did
Imported an 8-slide .pptx into Gamma. Every slide had speaker notes
attached in PowerPoint. I chose the faithful / as-is import option.
What happened
Slides, body text, and images all came across correctly — no complaints
there. Every speaker note was silently dropped. All eight cards arrived
with empty notes panels, and there was no warning during import that
anything had been discarded.
What I expected
Notes present in the source file land in each card's speaker notes panel.
Why this matters more than it looks
At 8 slides I just retyped them and moved on. That's why you probably
don't hear about this much. At 70 slides nobody retypes anything — they
conclude Gamma can't take their existing decks and they don't migrate.
The users this hurts worst never become users, so they never file a
ticket. I'd guess that's why this gap has stayed open.
It also cuts against your own docs. Your import article says content can
come in "exactly as-is." Your speaker notes article describes notes as a
first-class feature. Neither one mentions that the two don't connect,
so there's no way to find this out except by losing the notes.
The fix
PPTX stores notes in ppt/notesSlides/notesSlideN.xml, related to each
slide by an explicit relationship. Mapping that to the card notes panel
is a direct one-to-one — the data is already structured and labeled in
the file you're parsing. Google Slides and Keynote both round-trip
these on .pptx import and export.
Two questions
  1. Is speaker note import on the roadmap, and is there any timeline?
  2. Does the reverse work — when I export a Gamma deck to .pptx, do card
notes get written into the PowerPoint notes pane? I haven't tested it
and your docs don't say.