Yes, it does. In the event of divorce, in the absence of a prenup or postnup explicitly stating that the [83(b) stock or other income] is one spouse's separate income, the payment of taxes on a joint return is the single most important evidence of whether income is considered marital income or separate income, the legal reasoning being that a spouse would not have paid taxes on the other spouse's separate income.

It's also not clear what is "more complicated" about splitting marital property subject to an 83(b) election compared to other marital property.

The "more complicated" is in comparison to how 83(b) elections are treated if the spouses remain together. It's not a comparison to other marital property, though in general stock in a company that is not yet publicly traded can be extremely complicated to divvy up in a divorce.