So, in the linked complaint (not a full lawsuit yet, btw), they cite "breakage" where Starbucks corporate makes an estimate each year as to the amount of banked gift cards they reasonably believe will never be spent. It looks like it has averaged about $185M in the last few years. This can be moved from deferred revenue to actual, and thereby improve the financials. This could theoretically be fucked with on the margins and allow execs to pocket more money, and to some extent it obviously encourages Starbucks to promote gift cards (in the broad sense) over other payment methods.

The whole complaint is odd. Starbucks obviously feels like they have a winner in this scheme, and almost everything alleged in the complaint is kinda fucky, to the point that I think it's worth pointing out as a consumer protection issue. That said, the individual impact on any one consumer is very small and there are numerous workarounds for a slightly motivated person, and the tone of the complaint comes off kinda like pearl-clutching and paternalistic. Maybe you have to write it that way to make sure it's taken seriously, but it's not making for very persuasive reading.

Is that explicitly verboten? Can you not claim unspent gift cards as revenue?

I genuinely don't know, but if it's allowed or a business's choice, then I don't know what the hell the story is here. If they are doing shady accounting practices it's one thing, but if they are just reporting their revenue/profit from gift cards...who fucking cares?

Gift cards are, by design, a way for companies to increase revenue and profit. They are known to get lost and go unspent. That's straight cash for the company. The ones that get used, get used at the company.