I finally found a transcript of the earnings call on yahoo. Apparently the license "no longer match our business imperatives as it was negotiated". From the call it became clear that they intend to try to continue to renegotiate the license.
The patents on the AAV9 vector expire in 2024 in EU and 2026 in US. Whilst I hope MPS3A and 3B will be on the market well before then, given that the CLNs aren't in the clinic yet, they probably won't be marketed before patent expiry (at least in EU).
I guess it doesn't benefit RGNX to not agree a deal - it's not like they can use AAV9 to develop their own treatment from scratch for these diseases before the vector patents expire and ABEO would be able to launch their product. But on the other hand, they have all their other licensees (~15?) to consider. If they cave in to ABEO and agree to better terms, it might encourage the others to try the same tactic. I'm sure RGNX have more value adding things to do with their time than renegotiating done deals.
On a more positive note, EB-101 should fully enroll by the end of the year, data will be 6 months later, so they should be submitting their BLA in H2 21.