In my experience not many OTG devices actually used (mini-/micro-)AB ports, instead using just normal (mini-/micro-)B ports. The adapters generally just used a (mini-/micro-)B plug with the id pin wired like an OTG A plug. This does mean you can technically connect these adapters to non OTG products, which the spec writers wanted to avoid, but this simply meant the adapter didn't work.
I also have some peripheral devices with a captive micro-B cable (with ID pin configured like like micro-A) that were specifically intended to be used with OTG compatible phones.
I also have some peripheral devices with a captive micro-B cable (with ID pin configured like like micro-A) that were specifically intended to be used with OTG compatible phones.