I only wish it had a more... creative?... title, if it's going to be a sixth episode of OG Doom. "SIGIL II" would make more sense as a Doom II WAD that sees Baphomet and Satan at it again, honestly. But, if I trust anyone to handle yet more OG Doom and its limitations, it's Romero. I still think Doom's best maps were almost all his, though I think most would string me up for how much I actually like Perfect Hatred.
Against Thee Wickedly can spork right off, though.
At any rate, if I had to guess, the aim for this unnamed Doom II project is probably for it to be out late next year. Somewhere between the very end of September and the first third of October. Just a guess. No particular reason for it.
Edit: Today I learned the board censors that word, lol