I had a ten year gap so I really had these questions to consider in person :)
It was weird to see what had changed! I would say that the biggest changes really are:
Slightly different/stricter sleep recommendations especially for day and early evening sleep (I mostly ignore this, MNers generally explode if you admit this)
Rear facing car seats for longer (I followed this one, was aware of it before but they were vv expensive 13 years ago)
Oh but you'll need a mortgage to buy a car seat and/or pushchair.
Weaning seems much more complicated now - when we did BLW we just chucked food at the baby but it seems like people follow all kinds of rules now. I ignored these.
More tests available in pregnancy but you have to pay.
HV tests seem reduced in many areas - no great loss.
Parenting "influencers" are insane and all seem to exist to stoke anxiety/make you buy their course at ££££ - ignore them. Admittedly this is way easier to do as a STM because most of their sales pitch is about how your baby will never do this or that if you don't buy their course, and having a 12yo already you probably know this is a load of rubbish. But people fawning over them is baffling and annoying.
Facebook groups for parenting have gone totally insane and mostly contain moderators on a power trip. Don't trust them.
Gentle parenting for toddlers is now the norm whereas it used to be a crazy thing only crazy hippy parents did. I quite like this but OTOH there is still all the unhelpful permissive stuff.
There's still a war between baby routines vs just co-sleep and breastfeed them forever but now instead of books it's influencers 🤷♀️
Actually most things I did the exact same - the main difference is I actually went ahead and did the things I was too nervous to do last time - finally lived out my dream and bought a slide bed for DS2! Best thing ever 