Guild Wars 2

Is there any plan that guild upgrades will be available to guildies from other servers?

To me, this should have gone along with the mega-server roll out; however, that is not the case.

Per the Megaserver and guilds blog – they are working on it.

Yes.

’Because worlds no longer separate players, we’ll eventually make sure that guilds are no longer separated either, that every guild member will be contributing to and benefitting from the same unified guild chapter. Until this system is in place, your home-world guild chapter will continue to be the chapter where any influence your character earns is sent and is the chapter visible to you in the guild panel.

Knowing that many guilds stretch across multiple home worlds, we’ll be working to be as fair as possible when combining multiple chapters into one single guild for all members. All members of the guild will remain members when this happens, regardless of what world they called home. Please note that this will not affect the guild cap of 500, and we will not be able to combine separate guilds. This change will simply address how one single guild has a different copy on every home world.’

https://www.guildwars2.com/en/news/the-megaserver-system-guilds-and-the-future/

I don’t think so. Since the server is your guild home world, upgrades can only be applied there. People are already complaining about loss of server identity and this suggestion would make it worse.