Anon social media accounts

A bit of a hypothetical...

A good friend of mine along with their colleagues work for a large multinational company.

They are treated abysmally there. People are being let go with no notice and others are told to pick up the slack despite already doing things outside of their remit. This is causing indue strain in them. The company are cutting costs meaning things that are required to do the job are not working and they are told to just deal with it.

Recently she set up an anon twitter account to publicly call out the company about how they treat the staff, similar to the RogueWhiteHouseStaff Twitter account.

The senior management are all on twitter so she has called them out directly alongside the company and has tagged in the competition.

She has closed the account as she did not want her number associated with it as she been told that she can be identified if the company were to approach twitter, they partner very closely with twitter.

So my question is, can she be identified? Can twitter give the number or email used for that account to a third party who ask for it so that they can identify her or can she remain anon?