The long and short of it is that this talks about expanding product liability laws in the EU. Currently, software doesn't fall within the PLD, and software developers can shrug and say their software was provided as is if damages occur (e.g., loss of data, data leak, etc.), whereas manufacturers of merchandise are on the hook if their product causes damage (e.g., fire)
The EU says this isn't good enough and wants to include software in the PLD. This would only pertain to commercially exploited software (e.g., sold, provided with maintenance contracts, etc.), excluding tiny software developers.
The only relation this has to FOSS is that software developers that use FOSS in their product would need to, you know, make sure they know what they are including in their software (something they should do anyway).
This has zero effect on Joe Schmoe and their GitHub repo, but this lobbyist likes you to think otherwise to help him stop this change in EU regulation.
That's it.
0: https://www.bigtechwiki.com/index.php/Developers_Alliance