I hope our conversation was useful for you. As I indicated, the law is quite clear in saying that any transfer between phases of education (in your case, early years provider to school) must be done in accordance with a review of the EHC plan (in your case, this is essentially the formulation of it) including naming the school that will be attended.
This can be found in the SEN & Disability Regulations 2014 (paragraph 18):
Circumstances in which a local authority must review an EHC plan
18.—(1) Except where paragraph (3) applies, where a child or young person is within 12 months of a transfer between phases of education, the local authority must review and amend, where necessary, the child or young person’s EHC plan before— (a) 31 March in the calendar year of the child or young person’s transfer from secondary school to a post-16 institution; and (b) 15 February in the calendar year of the child’s transfer in any other case, and where necessary amend the EHC plan so that it names the school, post-16 or other institution, or type of school or institution, which the child or young person will attend following that transfer.
and also summarised in the SEND Code of Practice
9.179 An EHC plan must be reviewed and amended in sufficient time prior to a child or young person moving between key phases of education, to allow for planning for and, where necessary, commissioning of support and provision at the new institution.
The review and any amendments must be completed by 15 February in the calendar year of the transfer at the latest for transfers into or between schools. The key transfers are:
• early years provider to school
• infant school to junior school
• primary school to middle school
• primary school to secondary school, and
• middle school to secondary school