Bitcoin uses SHA-256, but I wouldn’t put it past some of the devs of some of the Altcoins and Shitcoins to use SHA-1 for either - or both of - their Proof-of-Work or Blockchain integrity hashing algorithms.
So if I understand today’s news correctly, you could use this to break blockchain integrity and offer-up alternative “valid” historical blocks (but not cheat at proof-of-work). You would still need to convince a quorum of network nodes to use your fake historical blocks - I imagine this might be doable on lesser-used coins that still have some trades - you could probably combine this with a few pump-and-dump trades too (without costing you anything as the coins you pump would be stolen).
So if I understand today’s news correctly, you could use this to break blockchain integrity and offer-up alternative “valid” historical blocks (but not cheat at proof-of-work). You would still need to convince a quorum of network nodes to use your fake historical blocks - I imagine this might be doable on lesser-used coins that still have some trades - you could probably combine this with a few pump-and-dump trades too (without costing you anything as the coins you pump would be stolen).