But the part about "insider information" and "might as well be considered part of the team" is complete bullshit.
I confirm. The core team is a fixed group of seven people, and they are not looking for new members.
There is/soon-will-be a separate group MEW, Monero Economy Workgroup, similar to foundation that some coins have. The group has tentatively 17 members, including me, and some but not all of the members of the core team.
As for inside information, MEW has a chat where Monero-specific news are quickly announced. If this sounds interesting to you, the membership of the group is open for all, as soon as we get some paperwork done.