From the official Porcupine Tree website:

Harridan and a few of the other new songs have been in play since shortly after the release of The Incident. They initially lived on a hard drive in a slowly growing computer file marked PT2012, later renamed PT2015, PT2018, and so on.
There were times when we even forgot they were there, and times when they nagged us to finish them to see where they would take us. Listening to the finished pieces, it was clear that this wasn’t like any of our work outside of the band – the combined DNA of the people behind the music meant these tracks were forming what was undeniably, unmistakably, obviously a Porcupine Tree record.
You’ll hear all of that DNA flowing right through Harridan.
Closure / Continuation
Produced and performed by
Porcupine Tree
Richard Barbieri
Steven Wilson
Gavin Harrison
( completed Sept. 2021 )

Tour

Porcupine Tree – Harridan (Official Lyric Video)

Harridan is taken from the band’s forthcoming eleventh album, CLOSURE / CONTINUATION – their first since 2009’s The Incident.
Over a decade in the making, CLOSURE / CONTINUATION is due for release on Music For Nations/Sony on 24th June 2022. It will be available as a seven track album on standard CD/double vinyl/coloured vinyl or limited cassette. The deluxe LP version comes on audiophile approved crystal clear vinyl as a 3xLP 45rpm boxset with two bonus tracks; the deluxe CD & Blu-Ray boxset comes with three bonus tracks, instrumental versions, and high resolution 96/24 stereo, 5.1 and Dolby Atmos versions of the album, all housed in an exclusive art book.

 

Order album here

TRACKLISTING:

DISC1
1. Harridan
2. Of the New Day
3. Rats Return
4. Dignity
5. Herd Culling
6. Walk the Plank
7. Chimera’s Wreck
DISC 2 – Bonus Tracks
1.Population Three
2.Never Have
3.Love in the Past Tense
+ instrumentals of the 7 album tracks
BLU-RAY – HD Audio / 5.1/ Atmos
1. Harridan
2. Of the New Day
3. Rats Return
4. Dignity
5. Herd Culling
6. Walk the Plank
7. Chimera’s Wreck

Source here

No news as to what happened to Colin Edwin. However in May 2021 a new company was registered under the name Porcupine 3, which only documents Steve, Gavin and Richard.