Why does Illustrator convert OTF to T1 ?

I created several maps and graphics in Illustrator using an activated OTF Adobe font (Acumin Pro). These AI files are placed into an ID document. I also use Acumin Pro throughout that InDesign file. 

When I preflight the file, with Type 1 fonts checked as not allowed, InDesign says all the fonts in the placed AI files are Type 1. But it does not flag those same fonts in the InDesign file.

However, when I export to PDF, every Acumin Pro font shows up in the properties as Type 1 .

Can anyone explain what's going on and whether I should be concrened?  I just replaced 57 styles in this publication with these activated fonts in preparation for the 2023 discontinued support of  postscript fonts, so right now I'm worried and confused.