Hi. It seems that there were no discussions specific to the subject for the last year. So would like to collect a summary regarding the following
There are few threads discuss those improvement you mentioned, such as :
MuSig: Schnorr Multisig and signature aggregationTaproot proposal [Schnorr] Should batched verification result in reduced weight per sig?- Current status of corresponding BIPs and its development
- Any kind of technical or economical obstacles for including into Bitcoin Core release
I don't join Bitcoin dev mailing or Bitcoin IRC channel, so i can't answer this one.
- New opportunities for business and users if that is released
Since all of those improvement offer reduced transaction size and privacy to some degree (except for Graphtroot which i never heard), there are few obvious opportunities :
1. Spend less Bitcoin for transaction fees
2. Prevent release whole script when spend UTXO (on MAST & Taproot)
3. Allow more transaction fit into a block due to reduced transaction size
4. Prevent de-anonymization by analyzing transaction (on Schnorr & Taproot)
5. Improve privacy for those who use mixers and CoinJoin
P.S. it's only high level overview