they also mentioned only having a 20K GPU cluster (unclear if NVIDIA, or Huawei).

A few quotes from the transcript:

Our current computing capacity is approximately 20,000 H-equivalent units, most of which have just arrived within the past month or two

Regarding the Huawei 950, Huawei currently provides us with 16,000 SIM cards

A Huawei 950 [cluster] with 16,000 cards is equivalent to only a B-series card [cluster] with 4,000 cards.