Currently only rich text content controls are available through Word API (https://docs.microsoft.com/en-us/javascript/api/word/word.contentcontrol?view=word-js-preview#word-word-contentcontrol-type-m...
Yun_Wang
Microsoft
Microsoftpascalbourut Thanks for submitting the request. Dropdown is in our pipeline, and I will update this post if there's new information.