Warner Bros

(the 2021 4K's 5.1 was flawed, with unnecessary bad tweaking)

But Warner Bros 4K Blu-ray is very similar.

4K Blu-ray caveat: mostly great video but the 4K Blu-rays have had additional DNR applied in some scenes on top of the DNR that had been applied in post-production and was already present on the DVDs & Blu-rays

The 2020 Blu-ray may be better than the 4K Blu-ray?

New Line Blu-ray have the original 6.1 mixes

4K Blu-ray set is missing extras from the old Blu-ray/DVD releases

• 4K caveat: A variety of VFX set pieces and touch-ups were added in scenes throughout the film, probably for continuity or consistency, although they might be unnecessary or revisionist. Clouds are added to clear sky of the last act.

• AI is used to fix an unwanted camera movement in one scene.

• some shots had been further stabilized, resulting in strange motion blur.

Also has missing dialog intact.
But it can be argued that the Warner Bros 4K Blu-ray 5.1 (remix) is technically a better mix.

More info on the different color grades over the years: https://notonbluray.com/blog/the-case-of-se7en/

Caveat: mostly great video but the 4K Blu-rays have had additional DNR applied in some scenes on top of the DNR that had been applied in post-production and was already present on the DVDs & Blu-rays

The 2020 Blu-ray (the one without the green tint) may be better than the 4K Blu-ray?

New Line Blu-ray have the original 6.1 mixes

4K Blu-ray set is missing extras from the old Blu-ray/DVD releases

The 2011 Blu-ray notoriously had a green tint, the 2020 one removes it.

Caveat: mostly great video but the 4K Blu-rays have had additional DNR applied in some scenes on top of the DNR that had been applied in post-production and was already present on the DVDs & Blu-rays

The 2020 Blu-ray may be better than the 4K Blu-ray?

New Line Blu-ray have the original 6.1 mixes

4K Blu-ray set is missing extras from the old Blu-ray/DVD releases

251 min cut (Extended): Fox Blu-ray. Eagle Pictures has forced Italian subs in some parts

229 min cut (Theatrical): WB Blu-ray

139 min cut (US theatrical): VHS

Eagle Pictures 4K Blu-ray, caps

The 4K includes both theatrical and extended cuts. It's overall a solid upgrade over previous discs, but some will strongly dislike the color grading.
There are some issues with encoding and grain management.

Nic's review:

Some definitely messed with it as there’s grain management going on that resulted in magnetic, squishy grain movement. Both cuts (4K discs) are affected and it doesn’t look like an encoding issue to me as the bitrates don’t drop down to single digits á la Paramount or StudioCanal. During opticals, the lowest I’ve noted on the Extended 4K was around 30 MB/s vs. ~5 MB/s more for the theatrical cut.

Darker scenes are mostly (but not always) better but when it gets brighter, particularly in exteriors or scenes like the Jennifer Connelly dance scene at minute 38, I can’t unsee the digital tinkering as it does some damage texturally.

I compared it with the Eagle Pictures and Warner Bros Fox Blu-ray of the extended cut and they all look fine without grain management like that. Eagle Pictures’s Blu-ray is an older one if anyone’s curious and credited to another authoring house than 64Biz, which did the 4K.

Other than that, except for some encoding-related chroma noise that peeks through in the DV layer, Eagle Pictures did everything right. They corrected the framing to 1.85, kept the original English titles, the English restoration note, subtitles, HDR/DV is gentle and respectful of the source black levels are better than on the Warner Bros/Fox Blu-ray. Without that grain management, this would’ve been the all-timer release we all longed for.

251 min cut: Fox Blu-ray (24-bit, Eagle Pictures is 16-bit, not audible)
229 min cut: Warner Bros LaserDisc (missing 2 minutes, but original mono mix was never released on DVD/Blu-ray)

Extended edition adds scenes cut from the theatrical, but from a much lower quality source. It's intended to approximate the original cut, but to what extent that is true is debatable.
US theatrical cut is infamously bad, was panned at release and never re-released on home video.

There are some questioning around the color timings https://fanrestore.com/thread-3435.html

The Ultimate Matrix Collection DVD/Blu-ray has extras not on the 4K Blu-ray box set

Different colors in the 4K compared to the DVD (both original and 2003)/2009 Blu-ray/Theatrical cut.

There are some questioning around the color timings https://fanrestore.com/thread-3435.html

WB 4K Blu-ray retains the revisionist colors with minor tweaks, has OG mono

Big improvement over old Blu-ray but controversial revised color grading

(caveat: "there's" in first "there's no place like home" utterance in final Kansas scene truncated)