These two pairs of tags are coexisting at the moment and one tag of each should be retired.
Regarding monero-history vs history, I prefer history but I noticed studycrypto have already edited a question to change in the opposite direction and so I prefer to ask.
For monero-research-lab vs mrl, the former is more common (7 vs 2) but I may make sens to keep the complete name since it seems to be used more often in the site and the papers (acronym is mostly used in the papers references such as MRL-0001)