re Python: "...All actual work is done by C libraries though, you could just as easily use BASIC instead"
https://excel.uservoice.com/forums/304921-excel-for-windows-...
Any long time developer on MS stack knows that actually means "thank you very much but no".
So, I would not be so sure.
As for Dex,
> Research language for array processing in the Haskell/ML family
> This is an early-stage research project, not an official Google product.
Where is Python?
But it’s also a google side project, so previous experience dictates that it’ll be dead somewhere between arrival and 5 years time.