With Xbench 3.0 build 1498 (announced here), we switched the Xbench Connector for Memsource to use the new Memsource REST API, as the Memsource legacy API will be deprecated in September 2020.
Since it was a complete rewrite of the Connector engine, we announced it but we decided to defer changing the “Check for new version” a few weeks in order to get some additional feedback (either assurance or customer-reported issues) on top of our internal testing.
In any case, any build published in our download page is considered to be safe to use in production, although we prefer to minimize the number of times all users are notified to update via the “Check for new version” feature, so there will be always are more builds published than notifications to update.