if you're updating to Bitcoin Core 28.0, then set the following flag to suppress a breaking RPC change that may prevent lnd from starting up:
-deprecatedrpc=warnings
otherwise I wouldn't hesitate to upgrade as this release contains some of the most consequential p2p updates for LN since segwit (1p1c and TRUC)
the sooner full nodes update, the sooner we can use the new features to make LN safer in high fee environments!