It would be a crying shame to lose the scores on Wizards in Winter. Some of the players in the community have obtained impossibly good scores on this map, and it would be highly unfair to them to unrank this.
My opinion on the matter of old maps, is that everyone has gotten a fair crack at them, so why shouldn't new players? So what if they don't meet the latest ranking standards? Also, it has been mentioned that some of these maps have really high attainable scores, but in order to get these scores, you need to be really good and really lucky. Someone who has acheived 16m points on Wizards in Winter (Rolled) has arguably earned those points and deserves for them to count in the ranking.
Finally, mapping standards are a continually evolving beast, based on the opinion of what's *required* of the majority BATs. As it stands, spacing requirements (which were needlessly strict for a short while last year) have become much more relaxed in the newest maps. Spinner requirements appear to be getting stricter, but still no attention is being paid to maps which use 1/4 timing to map music that clearly had a 3/4 or 6/8 signature. Those maps may be deemed "unrankable" if new BATs in the future decide so, but that shouldn't require old maps that failed to meet such a guideline to be deranked.
In short, if the map was rankable at the time then it should remain ranked, in my opinion.
Though honestly a good number of ranked maps, old *and* new, really could use some timing corrections