Possible licensing misunderstanding?

I have been trying to verify if the QWebEngineView component works with an all-round LGPL license. The header states LGPLv2.1. is the most restrictive licensing obligation to face, however, later on among the details I found an odd entry:

libcxx-pretty-printers: GPL v3

Reference

I am likely to be correct (okay, there is room for error, but I've been digging around the matter for a while) to say GPL is generally more restrictive, esp. in terms of linking with the covered products, than any from the LGPL series... is this a typo then, or is it something to take seriously? Is there a simple guide on how to omit this component?

"The module includes a snapshot of Chromium. As such, users need to respect the licenses of Chromium, and third-party code included in Chromium. The arguably most restrictive license to be respected by all users is LGPLv2.1."