Twitter has started 302 redirecting all URLs to use http://x.com as the default, a change from its previous practice of only migrating some sub-domains and shareable links. The use of a 302 redirect is likely a temporary measure to indicate to Google that Twitter is not fully ready for the change.
It is anticipated that Twitter will soon switch to a 301 redirect, which could cause some disruptions. This change might lead to Google temporarily halting the display of Twitter carousels, potentially resulting in a significant impact on Twitter's traffic.
