Did you know that Worf is over 110 years old at the start of TNG? Its true. He started his career as a defense attorney, defending Captain Kirk. He must have been demoted because he was a colonel back then!
That explains why he's so old in Picard.
Klingons must hover in youth / middle age for around 120 years, then undergo a rapid decline.
EDIT: In all seriousness, they should release an updated edit where they refer to him as Colonel Mogh.