To echo what's already been said, this isn't a final list, but it seems like PG issued this list as a way of announcing a whole bunch of the "minor" brands, as well as a way to reveal a lot of the returning vehicles from previous games.
What is a bit concerning though is the lack of consistency between this list, what we saw in today's stream, and the social media posts. For example, the #5 Escort and 917 LH were omitted from the Twitter posts, yet we see them being revealed in both the stream and the confirmed car list. I have a hard time believing that the licenses for those 2 cars took longer to secure, so that tells me there's some issue in communication between the Devs and the social media team, which isn't a great look. I'm sure there's several other examples besides those 2 as well.
On a minor note, DeBerti Designs looks as if it's being treated as its own manufacturer, so we'll probably get more vehicles down the line (there were strong rumors that the Drift Tacoma was supposed to be added to FH4 at one point). Hopefully the F150 will get its proper suspension, as it's a bit too stiff in FH4, and should behave more like the DeBerti Wrangler.
Also, unless this is going to be another oddly delayed reveal, it's odd that the F50 & F50 GT are back, but only the F40 roadcar is present, and not the LM variant.
Also Also, someone seems to have missed a typo or edit, because it looks like the Welcome Pack DLC will be returning, as the Bronco R has been listed as the "#2069 Ford Performance Bronco R 'Welcome Pack'."