So, there were rumours abound but I don't think any of it is nearly solid enough to count it as being revealed.
Destiny frequently referred to her as an offline girl who nobody would know - but it's likely this was obscurification to stop people looking.
There were many rumours it was Lauren Southern, on the surface this did seem the most likely woman because of their sudden content separation, but as of the recent divorce it's come out that Melina made Destiny distance himself from a lot of women out of jealously like Farha, so this isn't nearly enough to confirm it. There was also Counterpoints saying in a Twitch chat that he thinks it's true and Chudlogic reading it out, but neither of these are particularly trustworthy people.
All in all, it certainly never officially came out and on review there was never any credible enough leak worthy of confirmation.