It's brilliant if you're just starting but this is why so many experienced players are giving up.
Sorry, but some of us have been seeing this precise same announcement literally for
years. And not only is there no discernible change in the number of experienced players, but the very people who announce furiously that they are going to leave the game because someone has made an attempt to patch their favourite exploit (it's no longer possible for shields to reduce damage all the way down to zero in battles, for example, and the AI no longer targets rogues first in map battles or the PVP arena) rarely seem to actually do so.
When players give up, it is usually because their real-life family commitments become more important to them than some online game, or because they are simply bored of playing the same thing for years on end.
. It is the end of GBG (only 5 - 10 guilds will be able to play GBG
No, only 5-10 mega-guilds will be willing or able to go on farming GBG for chequerboard profit any more. The rest of us will have to get used to actually saving and spending our attrition wisely instead of never doing anything without guaranteed infinite zero attrition fights - which were never intended to be a feature in the first place. If you look back at the original discussion of the Guild Battlegrounds, the expectation was that players would battle until they ran out of attrition, not that guilds would routinely throw diamonds at insta-building siege camps (and nothing else) and swap sectors back and forth between each other at steady four-hour intervals.
In fact I seem to remember the GvG veterans of that era announcing that this would lead to "the experienced players giving up" because it would no longer be possible for a guild to defend its territory if shields dropped after only four hours, as opposed to holding for 24 hours after a sector was taken... of course in those days we were naive enough to assume that guilds would actually seek to hold and defend territory, as opposed to players making more profit by deliberately losing it to one another!