The grid actually already has a fair number of (non-software) circular dependencies. This is why they have black start [1] procedures and run drills of those procedures. Or should, at least; there have been high profile outages recently that have exposed holes in these plans [2].

1. https://en.wikipedia.org/wiki/Black_start 2. https://en.wikipedia.org/wiki/2025_Iberian_Peninsula_blackou...