Microsoft has updated its Financial products policy, now allowing Audience Ads for cryptocurrency exchanges as a pilot program.
This applies in all markets where Microsoft permits cryptocurrency advertising, pending pre-approval under the Cryptocurrency advertising program.

Previously, all advertising formats for cryptocurrency exchanges, including Display and Video/CTV ads, were prohibited. The help page reflects this change, stating that Audience Ads are now permitted, while Display and Video/CTV ads remain restricted.
Find the official announcement here: Microsoft Pilots Audience Ads for Cryptocurrency Exchanges.
This update was discovered by Hana Kobzová.