A $1.5m cleanout is just newspaper spin. If you aim to have most players on say an average of 3 year contracts (new players on shorter, established rep stars maybe on 4 year contracts), then on average one third of your squad should be off contract every year. One third of the $4.5m salary cap is $1.5m, so the "clean-out" story is rubbish.
It's just simple everyday squad management. Working out who is off contract at the end of the season, which of these guys you want to keep, for how long and how much, and what is the priority order of signing those deals (so you can know what you need to chase in the marketplace as the season rolls on).
Anyone thinking this potential "clean out" is a sign that the coaching staff has a plan is deluding themselves. It is simply the everyday dilemma that every club would face, on average, every single year. Pure spin.
Hindy (and Burt) should decide their own time they wish to call it quits, or what they can offer the club in the future. If Burt knows his time as a regular first grader might be coming to an end, he could sign for less and play a mix between Wenty and first grade - if he wanted to. Or he could consider retirement, or consider finding offers from other clubs. Same for Hindy, if he sees his future as playing less minutes and maybe contributing for another season from the bench (like Menzies), then he could sign for less (or consider retirement or finding other offers).
Either way, Hindy and Burt's choices shouldn't impact massively on the recruitment "plans" for the club, given any new contract might reasonably be for less cash, and with 10-year long service salary cap concessions in play as well. Bottom line, the club needs more of an actual recruitment and retention plan, rather than fumbling along on hype and Bentley's quoted expectation that players will come to him (or Kearney, or Osborne, or Anderson, or whoever is meant to be in charge of signings this week!).