After pasting a link to a tweet in a Webflow collection item and seeing the link not render as a tweet on a published site, I started embeding tweets in HTML blocks. After repeating the process several times, it seemed like a better option should be available.
Nelson Abalos Jr (aka "The Pixel Geek") offered a solution: Use the "Music / Icon" link option. It's faster than an embed and one can see tweets in context with other elements on a page before it's published.
There is a drawback though -- Tweets can be cut off if they are lengthy.