By the way I think the deadline for the prospectus obligation was Dec 1st 2020.
Prospectus Review | regservices.ch (one of the company that take care of that) mentions:
Art. 109 FinSO provides that a prospectus for securities offered to the public in Switzerland or admitted to trading on a trading venue must be published no later than six months after the authorisation of a Prospectus Review Office by FINMA, i.e. from 1 December 2020.
Edit: Seems like UBS stopped allowing people to trade US ETFs, when I check VTI in my account I get:
Ce produit est proposé uniquement en Suisse, ainsi qu’aux investisseurs domiciliés en Suisse, en possession du statut d’investisseur qualifié au sens de la Loi suisse sur les placements collectifs (LPCC). Il peut faire l’objet de restrictions ult.