Indeed. But the four bullet points seem to relate to provisions in the Licensing Act 2003, and s173 of that Act states that it doesn't apply for the purposes of being on a flight which is the subject of this thread.
Hence
Tobias-UK's statement (which
thbe objected to, but has not yet substantiated said objection) still seems correct:
....away from licensed premises (where the Licensing Act 2003 does not apply) the legal age for consuming alcohol is 5 years of age. This means there is no prohibition in law for those aged 5 and older to consume alcohol on board an English registered aircraft.