Once upon a time, I read something somewhere that indicated that change addresses had additional information posted in the blockchain vs third party addresses.
I suspect you are remembering incorrectly. The only thing that makes something a "change address" is the fact that the private key to the address is known by the wallet that is creating the transaction. Other than that, there is no way to tell the difference between bitcoins sent to someone else's address or to a change address from the sender's wallet.
I had long since forgotten about this, so I am hoping someone else can confirm whether this was ever true and whether or not it has changed.
If you can find the source of your information, I can let you know if the source is incorrect, or it you are just misunderstanding what they are trying to say.
Now as I understand it, in order to send coins to any address the network needs to be made aware of it by means of a transaction which will be forever recorded on the blockchain with the public keys of the addresses.
That is incorrect. The public keys of an address are not recorded in the blockchain until bitcoins received at that address are
spent. Unless you tell the sender what your public key is, there is no way for them to know it and therefore no way for them to include it in the transaction.
So what's the point in tranferring the coins to a new address if its public key is going to be made public by the transaction anyway, even if the address owner only made that single transaction using that address?
It isn't. You've misunderstood something.
so I have to believe that either A) I am remembering wrong or B) bitcoin core wallet was changed to not broadcast public keys for change addresses in transactions.
Public keys are available for addresses after a transaction spends bitcoins that were received at that address. There is no broadcast of the public key of an address that is receiving bitcoins for the first time.
