There is no concept of “zone” with the Octopus card. Basically anybody who lives in HK has an Octopus card. Its use is very much entrenched. It’s more convenient than any other “modern” payment method you can think of, including Apple Pay, Google Pay, Samsung Pay, Visa payWave, etc. The only limitation is the daily automatic top-up limit.

Which is to say that the desire for anonymity is the actual cause of the long queues, unless you think a lot of dark-haired and yellow-skinned foreigners who never had Octopus cards were flooding to the protest, which is unlikely.

Considering the history behind the Chinese government's response to protesters, I would be willing to consider that the title and related tweet is somewhat accurate.

Though I'd say that the hunch is right in this case, I'd be careful of falling into the trap of considering a news source more worthy just because it confirms your preexisting ideas.

Having been involved in the development and installation of the Octopus card, nearly everyone in Hong Kong has one. The card is valid on all public transport in the SAR (except the ferries and trams) and is also used for retail like 7-11 and equivalent.