one could argue that they did R&D as a non-profit and now converted to for-profit to avoid paying taxes, but until last year R&D already got tax benefits to even for-profit venture
so there really is no tax-advantage of converting a non-profit to for-profit
Otherwise, why do you think OpenAI is doing it?
Honestly it does not sound like anyone here knows the first thing about non-profits.
OAI did it because they want to raise capital so they can fund more towards building agi.