Raising the question which current Macs can drive it.
From Apple's web site:
"M4
Simultaneously supports up to three displays:
- Up to three displays: Two displays with up to 6K resolution at 60Hz over Thunderbolt and one display with up to 5K resolution at 60Hz over Thunderbolt or 4K resolution at 60Hz over HDMI
- Up to two displays: One display with up to 5K resolution at 60Hz over Thunderbolt and one display with up to 8K resolution at 60Hz or 4K resolution at 240Hz over Thunderbolt or HDMI
Thunderbolt 4 digital video output
- Support for native DisplayPort 1.4 output over USB-C"
But searching online found a couple of claims that all M4-based Mac Minis have HDMI 2.1.
If that assertion is correct, even a base M4 Mac Mini could potentially drive a 120-Hz 5K ASD, if it's released, but if your assertions of what connection types are required is accurate, it could only do so by HDMI, not Thunderbolt (4).
So at least the M4 Macs (that have HDMI) could drive this hypothetical new ASD. I wondered if they'd release 2024 line withholding TB 5 from the base M4 knowing this, but then again, maybe that added incentive to include it in the M4Pro and Max?
The M2 Mac Studio uses HDMI 2.0, but M3Pro and M3Max series Macs have HDMI 2.1.
My point is, the ASD is intended to be used with Macs, not other devices. Macs are already a niche market, a small segment of the total PC market. A 5K, 120-Hz display will effectively restrict the market for such an ASD to HDMI 2.1 Macs (M3Pro, M3Max, M4) or Thunderbolt 5 Macs (M4Pro and M4Max). For a possibly $1,600 (+ AppleCare+ and tax likely) that most users don't buy.
If this is all accurate, they need to release it alongside a new Mac Studio as a high end option. But how many of those users value 120-Hz refresh rates? I doubt they'll aim to game on it.