There is a reason why PVP events is most hated and lowest in participation :)) Same could apply for sieges, dont you think?
You gave "amazing" rewards for new elyos characters in hopes to balance population, shouldnt this start effecting power balance is sieges too? GP's isn't main problem in this server, power balance is for the last year the problem.
You trying to solve problem by cutting GP's and somehow throwing "inactive" people from top rankings and same time making sieges more active. What happens if people still not going to siege and same time you loose bunch of players making specifically elyos side even more unhappy, or same elyos just reroll to asmos side which is very popular thing to do these days.
You missed your chance to act on asmos domination for last 12 months, now fixing low participation in sieges issue by cutting everyone from arenas and making that content part irrelevant :)) Zerg rush type content just not appealing to me, and FORCING to go to the siege not going to work for me. GP trading is your issue, not players like me or any other random asmo/elyo, we shouldn't be forced to do anything we don't like (sieges) if you cannot find appealing ways to invite players into that type of content.
By cutting out parts of content you not going to solve anything, just alienate huge chunck of people and smartpants traders still gonna trade. If you want more active sieges - give permanent pvp buff to losing side and people maybe start seeing hope to win in even if they are outnumbered. Otherwise it's rip for the server.
PS. longer you don't give concrete information (reset date, is it repeatable and etc.), more people will be passive and eventually start looking for new server.