I took it as English being his second language and equating the top division of a country to being the "premier league", he'd coached De Grafshap and Zulte Wargram, clubs in the top Dutch and Belgium divisions immediately before going to Stockport County.
You are correct, that is exactly how I understood his statement. It is nothing to do with EPL. Many names of top Euro comps translate into English equally as Premier or as First, since the Latin root of "first" is, well, 'primus'.
For the same reasons"Prime Minister" in many countries is called the "premier" and that includes state government level in Australia.