Yeah, likely nobody, including Planet (nor, probably, MediaTek) likes this. On paper, we just lost about 1/3 of the CPU performance and more than half the GPU performance (though, in real life, thermal throttling and other power usage limits might make the actual differences smaller). I looked through the MediaTek web site, and currently, it seems no actual Dimensity 1000 (MT6889) exists in their marketing. The closest thing I found is a MediaTek 1000C, which, while said to have four A77 cores, still is limited to 2GHz and G57 GPU cores.
On the other hand, that 1000C specifies a max memory frequency of 1866MHz, while the Dimensity 800 is said to support up to 2133MHz (though we don't know what speed Planet refers to as "ultra-fast"). Also, just because MediaTek lists a 1000C, that doesn't say it's actually available. I suppose the same goes for the Dimensity 820, which, while still "only" having A76 cores, supposedly can reach 2.6GHz, and while "only" having G57 GPU cores "at least" has five of them. Had that chip actually been available to buy, I can't see why Planet would settle for the 800.
Personally, I couldn't care less about the lower theoretical up- and download speeds, as, at least here in Sweden, neither any broadband nor cellular networks, even in theory, seems to support anything even close to those speeds anyway, but your mileage may vary, as they say. Oh, well, the joys of supporting products before they actually exists, I guess. The Astro will still be faster than the Cosmo, which, for me, is fast enough. I just wish it wasn't as buggy. At least the Astro won't need that seemingly cursed CoDi... and it seems we might be getting UFS instead of the old eMMC. That should make the built-in flash storage a bit faster.
I'm wondering a bit about that BLE Audio. Officially, that seems to be a part of Bluetooth 5.2 and, as far as I can see, all MediaTek smartphone SoC supports, at most, 5.1, though, maybe it's possible to support 5.1 and BLE Audio, without offering full 5.2 support? I don't know. While I think the Bluetooh 5.2 LE Audio codec LC3 seems appealing, I'm mostly interested in significantly lowering the latency, from the ~40ms that seems possible today, to well below 10ms, for real time audio purposes. That seems to require the LC3+ Codec, which, as far as I know, isn't a mandatory part of any BT specification version yet, so I guess I wasn't going to get that, even if the Dimensity 1000 was real.
By the way, Update #18 has already arrived, requesting questions for a "first look" Vimeo video on January 19. That might be an opportunity to ask for clarifications.