No, they are not.
There were two changes in Ventura. First, Apple changed the “availableFonts” so that it no longer returns supplemental fonts. Next, Apple changed the enable/disable methods such that they no longer work on supplemental fonts.
And I have no reason at all to disbelieve your account of what Apple has done in Ventura's background. I'm just saying I've tested this over the past couple of days, and some apps still show all of the Supplemental fonts no matter what you try to do.
The Typeface font manager just flat out tells you the Supplemental fonts cannot be disabled. FontBase and RightFont both let you add the Supplemental fonts to their interface, and both act as if they're disabling the fonts when you choose to do that. But in both cases, the fonts are still active. If they were truly disabled/inactive, then they wouldn't continue to list as available in the Adobe apps. But you already know that as you plainly stated, "Apple changed the enable/disable methods such that they no longer work on supplemental fonts."
Overall, though (of those apps I have on my Mac I can test with), almost all of them now hide the same fonts Apple does. Including the new free version of Outlook.
Of the apps I could directly test, without randomly downloading other apps that present a font list, only these still insist on listing every single font in the System folder:
Adobe Photoshop (and I presume the rest of the CC suite)
Master PDF Editor
SoftMaker Office
Of those, SoftMaker Office is the oddball. It has a bad habit of directly reading the Fonts folders instead of listing fonts flagged as available by the system. The good news there is the 2024 suite is in beta and they've made some very good, and necessary changes. One is the suite never used to pay attention to fonts you activated in place. They had to be in a Fonts folder for the apps to recognize them at all. I noted this issue as something they really needed to address, and darned if they didn't have it implemented in the very next beta release.
And like the MS Office suite, you had to shut down and relaunch the apps for them to even see a font you activated if the app was already running. The beta now recognizes newly activated fonts immediately. Though like MS Office, it still doesn't recognize when you've disabled a font when the app is running - sort of. It does the same thing MS Office has done for decades. It knows the font is disabled, but still shows the font name in the list instead of clearing it. You still have to shut the app down and relaunch it for the disabled font to disappear.
They also added a button to the preferences:

Before, you had to go through the list and uncheck every single system font you didn't want the apps to show. Like all of the Noto fonts, Saravek, etc. Now you just turn on the new check box below the list and boom!, all of the same system fonts Apple hides are no longer visible. All good except they need to fix a bug where if that box is checked, then any third party fonts you enable, no matter what method used, never show up in the font list. Otherwise, they now have that nuisance covered.
This change certainly seems to have reduced the frequency of this kinds of posts. Curiously, it did not eliminate them. But I’m still skeptical. The only font listing that the OP seems to be complaining about is the list on a web site. Sorry, but that just doesn’t count.
I have to admit I don't what web site list you're referring to. I went back through the OP's posts and don't see a reference.
As far as Adobe goes, they are clearly the holdout. You know they have the expertise to easily enable the same API's as anyone else, but seem to be deliberately ignoring it. Couldn't tell you why, other than the guess I threw out earlier.