Do maiko and geiko who have had their misedashi or erikae this year qualify to recieve an award at Shigyoshiki this coming January? Or would they have to wait a full year in order to qualify?

Yes, they can still win awards at Shigyōshiki. An erikae has no bearing as the woman would still have been active at the beginning of the year as a maiko and becoming a geiko doesn't change her active status. As for new maiko, it's harder for them to chart during Shigyōshiki since most didn't debut until mid way through the year, but it's not impossible if they work hard and become popular ^^