trust only works in retrospect (it can't be extended into the future to a party simply because they make a promise)

all such relationships have an expiry date (since as the trusted party evolves or needs to reinvent itself to satisfy shareholders). what can prevent this are bullet-proof contracts (that's not how people make decisions though - they never read the fine-print, review it when it changes and instead work on gut-feeling and emotions).

putting your trust into a brand/product is always going to eventually hurt you. A product having reached the size of Signal will most certainly throw part of it's user-base to the curb if it thinks it's held back by their opinions/goals.

The disconnect is people thinking Signal owes them something (when everybody actually used it for free until now).