It’s the “embedded controller”. I think it’s main purpose is to control the charging levels, battery management. It’s new in the L5 and L14 and enables more fine-grained control on battery management.
Nicole mentioned it in several posts, e.g. Widespread laptop manufacturers fetish for plastics and non-glass screens - #8 by nicole.faerber
As PureOS is based on Debian, you don’t miss any eyes. The fixes in Debian are downstreamed to PureOS, and the fixes in PureOS are usually upstreamed to Debian (however, that does not mean that novel develpments like for the EC, will end up in Debian stable any time soon).