I recently heard that an Inform v8 is being tested and soon to be released.
Is this true?
No. It’s still going to be called “Inform 7”, and no release date has been announced.
Graham Nelson has discussed progress on the next release of Inform 7; see this presentation from 2019: http://emshort.com/narrascope/talk.html
He had originally planned to release it last fall, but that didn’t happen. He has another talk planned for this coming Thursday, which you can watch online: http://narrascope.org/pages/schedule.html#ThursdayB
If it’s close to release, he’ll tell us then.
Will check out the talk for sure, thanks for the heads up! Hope to hear an update regarding open source efforts for Inform7.