Here's the Tweet that kicked off a Twitter thread regarding the prompt to rebalance:

Electrum 4.3 will suggest a channel rebalance or submarine swap if it can help receiving a payment.

Electrum prompt to rebalance

https://twitter.com/ElectrumWallet/status/1555642692901765121 https://nitter.it/ElectrumWallet/status/1555642692901765121 <-- Shows the thread in a single, easy-to-read, web page