Players and clubs are mostly grown-ups about this sort of thing these days. The discussion has probably gone along the lines of:
i. Brisbane is looking for an inside mid and has had a pretty long run of selecting kids early in the first round (many who want to go home in a few years).
ii. Neale is one of the best inside mids in the league, and at an age where he next contract will likely take him to the end of his prime.
iii. Brisbane spoke to Neale’s agent, who probably said something like ‘he’s happy enough at Freo but I’ll ask Lachie the question. What sort of deal would you be offering?
iv. Brisbane probably offers more than Freo (as they would need to in order to entice him).
v. The agent speaks to Neale, who probably says he is happy at Freo but wouldn’t say a hard no to that sort of deal.
vi. The agent and Neale know he is under contract, but he is an unrestricted free agent next year, so they approach the club and ask whether there is a world in which a deal would get done.
vii. Freo probably says ‘we’d hate to lose you, but if you were keen to go, we’d want at least their first round pick for you know rather than lose you for nothing next year’.
viii. The agent probably gets on the line to Brisbane and says something including the top 5 pick would maybe get it done, so it’s probably worth having a chat about this in trade week.
ix. The agent knows that even if Neale doesn’t end up in Brisbane, it’s not the worst idea to give Freo a sense of his worth to other teams in the league.
I don’t see anything wrong with that sort of discussion, and it’s not one you can easily shut down because, realistically, anything is possible. You could read all sorts of things into the rumour, but it’s just as likely this isn’t indicative of anything other than an agent doing his job, two clubs appropriately valuing Neale’s worth, and a player keeping his options open.