If we're enumerating, so far, you have - just off the top of my head:
- Taynor's mage consortium quests
- Ironworks employees fiddling with the beacon
- Greg's portal at the end of SB
- The CT quest series / WoD 24-man necessitating lots of help from multiple adventurers
- A bevy of crossovers and quests from 2.X-4.X, from events all the way to PVP
All with ingame written lore and flavor text. All setting precedent for interworld travel, even if some roleplayers refuse to acknowledge them. Yoshi-P outright adjudicating "yes, non-WoL normies can" to a question so directly steeped in the lore and current storyline corroborates the above. Someone not liking something about the setting for the game they're playing in doesn't change that it's been established in canon as either having happened or continuously, repeatedly ongoing.
People openly discussing their activities on the First - mind, the interviewer made very sure to explicitly ask for non-WoL adventurers / normal individuals - is well within established RP boundaries with precedents. It's just the latest in a series of clarifications that the devs have laid down over the years.
"Only the WoL can fight primals."
"Actually, Echo user and SMN teams can. And often do these days without the WoL."
"Only the WoL can solo through primal trials / World of Darkness / Orbonne / Isle of Val."
"Actually, bigger teams of other adventurers are needed to accomplish those."
"Only the WoL can travel between worlds."
"Actually, normal individuals can, too."
Again, people not liking something established about the setting doesn't change the fact that it's been decisively established. There's no winning or losing at lore, there's just the sum total to date of what the devs have stated externally and/or put in their game. Some people will just continue ignoring / nitpicking / rejecting specifics that don't suit their worldview.
Whenever the devs make a clear-cut ruling like this to end a debate, I'm always reminded of when people went nuts because Pluto was decided by authorities to no longer be a planet. You might not like it, but it's been decided. And/or had precedents set for it.