Remember that HA and TA are still in the Learning Schools Trust until September - it's perfectly possible that parent, teacher or governor representatives of other schools will join, be co-opted, etc. later on.
But yes, the TA headteacher is experiencing this as a sort of takeover, because that's how schools get transferred from one trust to another - they don't exist in their own right. I remember googling her a while back and seeing that she had a coaching business, so maybe she can go back to consultancy work very quickly.
The letter in the RTT is quite a rant from what looks like an exhausted teacher - but most of the points covered apply equally to academy and LA maintained schools (spending money, supply teachers, bullying, SATS, complaints procedures, OFSTED, teaching unions). He/she doesn't like unions, but there is a choice of them, and private school teachers belong too to get liability insurance and be properly covered by the pension.
The main point made relating to academies was that 'Academies need a business person at the helm rather than a teacher.' I'd like those at the helm to have a mix of education and management expertise, but the real issue is of accountability which the letter does not address.
You'd think that someone like the CEO of AET has the perfect background to operate a large trust (teacher turned barrister, ex-Director of Education, experience as chief operating officer of ARK and adviser to other trusts and the Saudi Arabian government...) but the leaders of our Tory council are furious with him and AET and do not see the advantage of remote-managed large chains which have been severely criticised by Ofsted.
Then there's John Nash who appointed an unqualified teacher as head, who then left after 6 weeks into term, and the Tory Party donor and businessman Alan Lewis who the DfE assumed for a year was chair of governors at Kings Science Academy but apparently was just the ‘patron’, and is still the landlord. Where there is no oversight over the trusts or accountability to local communities, having a business person at the helm can be a positive disadvantage when large sums of public money are at stake, rather than a benefit.