No, it wouldn't. The EU is a wholly separate institution and rather younger (although one could argue about its legal predecessors, the EC and EEC in reverse chronological order)..
The ECHR was founded in 1959 in part by, er, the UK. Being a signatory to the European Convention on Human Rights (circa 1953) is not related in any way to membership of the EU.
This is just as well because it means we can stay in the ECHR and leave the hotbed of fraud and featherbedding far behind.
Biting the hand that feeds IT
