I have worked for a medium size ISP for many years (3 upstream Tier-1 provider, presence on 2 IXP) and we sometimes suffer from BGP hijaking.
We had developed a software that every hour checks the BGP prefix assigned to every peer and update the BGP filter automatically.
It takes some time to engineering it and develop but after then, it works like a charm.
It's a shame that the ISP is bankrupted, it could be a very nice product also to sell. I was in charge of this software, I can reproduce it easily (unfortunately I don't get the source code) and put online then everyone can use and improve.
Those are very expensive.
According to apnic[1], there are 15,000 update / day in 2016.
For small size ISP, the number is much lower and may be managible. But event driven can't be a general solution for larger isp.