(Using java as an example, but this is applicable for any language)
x years into the future when it's almost-absurd* to be writing pre-Java-7/8 code without generics, try-with-resources, streams etc., will we then delete the java-8 tag synonym?
This question applies in the present context too, if a user says 'I need a review on this Java 1.5 code, because the other bits of my application/framework are horrendously stuck on J2SE5 SDK/JVM', are we inclined to create a 'java-5' synonym now, only to delete that in the future?
TL;DR: how do we manage the lifecycle of tag synonyms, in the present and future?
* - yes... I know, legacy codebase usually rears its ugly head more often than expected, but let's assume my example is in the ideal-world scenario...