I've experienced yesterday a few 60s trying to justify that this change is bad, they kept implying "Oh, you don't get it why it's bad" or "So many raiders are leaving after they heard this change" while alot of other people came up with legitimate answers on why it would be beneficial.
There are several reasons why the x7 exp for a month will have legitimate negative consequences, and they were mentioned in World on Horde side several times. Summed up quickly...
1) The server was advertised and launched as a x1 blizzlike WoW offering to capture the original game from 2004-2006. Fans of the server that made the grind to 60 and remained to stay on the server liked the choice they made with what the server was developed for, and see a full month of x7 as a 'bait and switch' to what they were promised.
2) Multiboxing is allowed here, without 3rd party keyclone or automation applications. Competitive guilds (and one in particular) previously abused level 20 warlocks to gain an edge with world boss raid targets, to the point where the lead Admin stepped in and made a non-blizzlike change to the server which generated quite a heated thread. It's on this board a step below - perhaps you missed it. The x7 month will negate this entire situation as multiboxed warlocks from raiding guilds can be taken from 1-45 in a matter of a couple of days at most. Especially with the use of AoE grinding in instances. Automated boxing in instances will go unwitnessed by all. GG.
3) with the above situation, people seeking to generate high level characters to sell, either through the Twinstar auctions or on the black market will do so with ease. Nothing to stop them. x7 is a HUGE value to work with, if you've never experienced it before on a private server.
4) Numerous players (including myself) might take the full amount of time to level alts to 35+ simply for tradeskill reasons such as Alchemy transmutes. Hardcore raiding guilds will do this for obvious reasons, and this will have an impact on the alchemy transmute economy when it's done, and it's going to have a server effect past the time of the "it's just for one month" duration.
5) Lastly, new players attracted to the server that join AFTER the month of x7 is over will be met with a sharply top-heavy leveled player base, and it's incredibly unfortunate that the maturity of many of our players is low. Instead of being happy with these new players, they'll be sought out for PvP griefing as the new players level which will make the new players say "WTF? why so many bored 60's?" - and then they'll find out about the x7 month, and then they'll wonder why the server was offered as Blizzlike and how this server is any different from a certain successful rival server.
Those are just 5 off the top of my head. I AGREE that the server needs new players. I AGREE that this x7 boost will bring them in. I DISAGREE that there will be NO lasting negative effects of the full month long boost. People are failing with common sense if they think there won't be any.