Are you referring to this topic?
If true, those mentioned exchanges are the available ones on T212.
Yes, to add a new stock/ETF, it must be:
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Listed on an exchange already available on Interactive Brokers and;
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Listed on an exchange already available on T212 (exchanges are mentioned on the above topic).
IB has access to several exchanges, but not all of them are present at the moment in T212. T212 is periodically adding new exchanges (that topic is updated accordingly).