Can a minority shareholder bring an oppression claim after a controlling shareholder's estate takes over the company?

Yes — a minority shareholder isn't automatically shut out of the oppression remedy just because the person now controlling the company is an estate trustee rather than the original controlling shareholder. Ontario's corporate law lets a shareholder apply to the court where the company's affairs have been conducted, or a power exercised, in a way that's oppressive, unfairly prejudicial, or unfairly disregards their interests, and courts assess that against the shareholder's reasonable expectations rather than requiring proof of bad faith.

An estate stepping into control can trigger exactly the kind of conduct this remedy targets — for example, if the estate trustee changes how profits are distributed, excludes the minority shareholder from decisions they'd previously been part of, or otherwise reshapes the company in a way that unfairly disregards arrangements the minority shareholder relied on. Whether a particular claim succeeds depends heavily on the specific facts, the company's history, and what the minority shareholder could reasonably have expected going in, so success isn't guaranteed just because control changed hands. A minority shareholder in this position should get legal advice promptly, since available remedies and timing considerations can be affected by how quickly they act.