This is a bummer because high availability is really important for many search uses cases. For e.g. think about e-commerce where search literally prints money.
EDIT: it seems like the open source version supports a read-only replica for failover but my overall thoughts about not crippling/compromising the clustering story in open source version still stands.
While I understand the rationale for this move, unfortunately not having HA in a non-starter.
I had a similar temptation when open-sourcing Typesense (https://github.com/typesense/typesense) and thought long and hard about keeping clustering as part of a closed source commercial edition but eventually decided against it. I understand that commercialising certain features is a necessarily evil and trade-offs must be made. However, I think there are still many avenues to do that without keeping clustering closed source.
Apart from that, I am happy to see the search space heating up with a lot more interesting options.
Disclosure: I have stakes in the open source search eco-system (https://github.com/typesense/typesense) but a genuine Redis fan.