Here is the announcement time for the new Zeiss, Sony, Sigma, Panasonic products

Above: Leaked Panasonic S1rII info

This is when to expect the official product presentations:

Sigma: Feb 25, 1pm Berlin time (maybe a new 800mm f/6.3)
Zeiss: Feb 25, 2pm Berlin time (Otus 50 and 85mm f/1.4 RF-E-Z mount lenses)
Panasonic: Feb 25, 3pm Berlin time (Lumix S1rII, 44MP, 40fps, 8k)
Sony: Feb 26, 3pm Berlin time (16mm f/1.8 G and 400-800mm f/6.3-8.0 G)

Also Cosina, Viltorx and other lens manufacturers will announce new lenses between Feb 25 and Feb 26.