No, but we can extrapolate based off toy release dates and the scan pictures.
Freezing Bear's Key, for instance, is coming out on either the 12th or the 19th, corresponding to the 7th or 8th episode, and scan pictures show it fighting against the Mammoth Maiga. Breaking Mammoth itself should be debuting in episode 9, since its toy should be out on the 26th.

Kamen Rider Jin's Flying Falcon form is his default and has the strength and abilities of a falcon. It can fly in the sky at high speeds and cuts opponents with its sharp cutter.
Kamen Rider Horobi's Sting Scorpion form is his default and has the strength and abilities of a scorpion. It can take away the lives of people with the venom flowing through its body.

Breaking Mammoth has three modes; satellite, jet, and robot form. While in orbit it stays in satellite mode and then transforms into jet mode when entering the Earth's atmosphere ultimately changing into robot form for Zero-One's Breaking Mammoth form.

Well SHF Autovajin are transformable so the SHF Zero-One Breaking Mammoth have transformable function is possible.

What are the henshin poses of Horobi & Jin? And how do their drivers work to transform?

Possible? Yes. Probable? Absolutely not :lol

Seem pretty straightforward, insert the (closed) Progrise Key, pull the lever, the Driver opens up and the key opens alongside of it.

I think before asking about whether Mammoth will be made or not we should probably ask how well did Machine Itasha sell first.

Can we approximate Jin’s first appearance using this method as well? Unfortunately I’m not sure when the driver will release.

I have the Auto Vajin and it's awesome

Also... we did get SOCxSHF Itasha Robo, which was ...ludicrous

But where is my Watermelon Arms?!!

Unfortunately not, the ForceRiser Riders are debuting well ahead of their toys' release dates (their toys are out on November 2).

I would assume it'll be the one episode that doesn't align with other debuts, though. We just got the titles for episodes 6 and 7, which pretty much locks down Freezing Bear's debut as episode 7 (since the title is "I'm a Hot-blooded Humagear Teacher" and TV-kun says the Mammoth Magia was originally a teacher Humagear). Since 9 should still be Mammoth, that leaves episode 8 as a bit of a blank. It'd make sense if the stuff with Jin was then, but hard to say for sure.

edit: gonna make a small correction and say I'm like 50% surer now that Jin's debut is gonna be episode 8. I hadn't noticed before, but the Lightning Hornet scans show her fighting the Dodo Magia (which is almost definitely the villain in episode 8) in what appears to be the same location that she's shown with Jin in a separate scan. He could technically still debut before that, but I'd put 8 as the maximum latest episode.

Quick question: That would mean the Freezing Bear Progrise Key is out October 12th, correct?

Do you know which episode has Valkyrie' Lighting Hornet form in it? Because I'm trying to get both the Bear and the Hornet keys, and it would be ideal if I could bundle them with a shipment that goes out October 19th.

Freezing Bear should be no problem them, but I don’t have any clue when Lightning Hornet drops.