OP, SMH at your and PP's disproportionate and unevidenced blaming of the bride over the actual tool who chose not to prioritise inviting you to his wedding.
If the bride-to-be has any error here, it's that she chose, for a life-partner and the father of her children, the kind of self-serving man-child who sponges off his parents despite being a grown man with a child and who, when presented with a significant financial opportunity to better himself, increase his earning capacity or secure a home for his family to live in, opts instead to throw an self-aggrandizing, showy circus of a stag-do and wedding with the funds then continue on sponging as a married man.
She prioritised inviting her family members over an excessive number of bridesmaids, suggesting she does place some value on both family and propriety.
He prioritised having a chorus line of white-clad attendants, parent's NDNs etc.
For all you know, the bride-to-be did say something during the planning stages, and he dismissed it.
You made it clear that he was pushing for - and has heavily influenced the planning of - this big wedding from the outset.
You also made it clear that the bride-to-be is quiet, less assertive etc. He clearly drives the train in their relationship.
...He certainly doesn't seem like the kind of person who listens to advice that counters what he wants, based on his response to you and your family.
But now you are in danger of performing the oh-so-common mental gymnastics performed by in-laws the world over that shift the responsibility, resentment and blame for your biological relative's behaviour (or the couple's behaviour together) onto the in-law, to rugsweep your bio-relative's bad behaviour and avoid facing the pain that they actually do suck/don't value you.