The original idea of having many small-sized instances is already failing, also without Meta. Small instances are unreliable (they quit/shutdown), have major sync issues (not seeing all replies, boosts etc) and have a tendency for too restrictive moderation and defederation.
So indeed, most people (normies) will naturally flow towards larger and more mainstream instances. It's already tilting in that direction and actively encouraged in the signup process.
As these instances grow, they will simply have more disagreeable posts (from the perspective of the ideological instances) leading to even more defederation, hence the split will become ever harder over time.
