They have the option to splice out the inbound liquidity you rented. But it you used most of it to receive payments, then nothing happens. They have to pay the on-chain fee to splice out any unused inbound liquidity after the year.

Splicing is starting to happen!

Don't sleep on Eclair if you are investigating setting up a professional routing node.

ACINQ runs one of the largest nodes on the network and their node software is (of course) open source. They have been running a large node for years, so much of the necessary optimizations and features already exist for running a large node. Eclair has been battle hardened over many years.