Not a lot. It's a tool that tries to write code for you, based on code it's
seen before. A bit like 'predictive text' can guess what word you meant to
write next or maybe finish your sentence for you.
The article above is querying the legal status of such code, and whether it
amounts to plagiarism. A bit like having a computer read someone else's
novel and suggest you write words that might have similarity to words it has
seen from another author. It makes the idea of 'authorship' very
complicated, which makes the legal status unclear (in particular, can
Microsoft claim any credit? Should they get royalties for every novel
written using their tool? Does the author of the source material get a say
in this? etc etc). The article suggests a boycott is a way for developers
to signify their displeasure.
The tool is probably not going to work very well writing RISC OS software
since it won't have been trained on RISC OS code - maybe ok for generic C
but not for SWI Wimp_Poll... It'll be like having the tool suggest English
words while writing a novel in Swedish.
But the use of the tool is entirely optional, so RISC OS folks can continue
using Github to host their software if they wish. As mentioned it doesn't
affect ROOL who don't use Github.
Theo