Thanks all for asking about this. We no longer support partial version aliases for new versions of libraries. Any partial version aliases already in place will continue to be supported and updated. The reason is that URLs like
https://ajax.googleapis.com/ajax/libs/jqueryui/1/jquery-ui.min.js which is saying "give me the most recent version of jquery 1.x.x) have very short cache lifetimes since the most recent version can change at any time. This is bad for performance. This is also bad for your web site, in the event that a library makes breaking changes in its APIs between versions that cause your page to suddenly render differently. Libraries do not usually make such changes intentionally but pages sometimes depend on behavior of an unspecified corner case of an API that may be changed intentionally or inadvertently as the library is updated.