I would agree. Wherever you end up, you'll probably get doted on by the FAs, but I wouldn't expect to get anything "free" for the sake of being pregnant. You could ask about paid upgrades, but we're generally past the day and age where GAs will give folks unsupported upgrades just because you have a special circumstance.

From my personal experience, I flew 3 Y segments between 32 and 33 weeks just this past June (due date is this Sunday!), and in each case, I inquired about paid upgrades. I went 0 for 3, paid or free.