I dont think it will cause to much of a fuss from people if you reset the high rate man, I mean its a high rate server, people expect them to be reset. Plus after lvl 100, there isnt much to do on a oldschool highrate but pk, and people get bored eventually. First few weeks of this server, you had a good player amount at all times of the day and night online, now that its been on a few weeks, and most people have reached 80+ .. servers gotten a lil more boring and died off, its obvious people are bored of it. Reset it like everyones wantin and you'll get your players back.
If your wantin to keep a high rate server alive and online longer with a decent player amount, reset it but lower the exp stages some so its not so easy to take 90 in a couple days, thats just my opinion though.