Of course it would be nice if companies focused on diversity, and I think large companies should definitely think more about it, but telling small startups to do it is wrong at best and exploitative at worst (personal agenda).
I would like to know of any successful company that focused 25% of their time thinking about diversity during their early startup stage. Thinking about diversity 25% of the times means you're thinking less about your customers 25% of the time. This type of company will probably not be around the next year--Congrats, your diverse company is now gone! I'm sure your employees are all happy!--So I wonder where she pulls "if you're an early stage startup with little to no diversity, you're in trouble and need to fix it fast." out of. There's no evidence, and logically it doesn't make sense. It's just her own entitled sense of justice (which I don't even believe is genuine).
I'm not saying diversity is not needed, I don't think it's right to capitalize on social trend by misleading the public. Basically the narrative nowadays is "Let's shame and punish all these companies that are not thinking about diversity", and I think that's as bad as those companies neglecting diversity, in a witch-hunt sort of way.