An IPO of Raspberry Pi Trading Ltd would unlock a lot of funds for the Raspberry Pi Foundation which could be reinvested into further educational activities. It’s probably a good move for the original mission of the foundation.
It would also make every decision that the company makes from here going forward one of fiduciary responsibility to the shareholders. For a project rooted in affordable open-source hardware/software that's a major conflict of interest.
I get that "Raspberry Pi (Trading) Ltd" is not the Raspberry Pi Foundation, but it is wholly owned by the foundation as a subsidiary. IMO, it'd be of major concern if any RPI business entities went public.
Either way, your "as long as..." conditional statement may be logically consistent, but the condition is by no means guaranteed to be met.
Nonetheless, a lawsuit is possible as well. Foregoing profits in favor of ideology could conceivably be a breach of fiduciary responsibility, a primary cause of shareholder lawsuits. You may be right that there has never been a lawsuit like this about too-low prices, but I simply don't know. And unless you're a corporate lawyer with extensive shareholder lawsuit experience-- or happen to have some legal experience and a subscription to something like Westlaw-- then you are making an unfounded guess.
I have a friend w/ Westlaw access, among other databases, but I'm not willing to ask them to spend a few hours researching the issue to see if there's every been such a case, or try to find one myself. But in the history of corporate lawsuits it certainly wouldn't surprise me. There is a body of caselaw that could encompass it, predatory pricing (https://www.justice.gov/atr/predatory-pricing-strategic-theo...). Selling significantly below the market-clearing rate demonstrated by scalper prices might provide some ammunition for this claim, but IANAL so I won't speculate further on its actual applicability.
If you have more direct expertise or knowledge of the caselaw there I'm happy to hear it. I think, absent completely recalcitrant corporate leadership on the issue, shareholders would force the issue outside of the courtroom.