I think it's quite possible, though by no means certain, DEI is a main reason they are having these issues. See the last post in the Twitter thread about their supplier Spirit Aerosystems.

The argument about cost cutting sounds less convincing to me. Compromising on critical safety will only save cost in the short term. But both Boeing and their suppliers have more incentive to optimize long term cost. They are not in this business for a short period of time.