Yes, they can trade. From the 13D: The Reporti

Yes, they can trade. From the 13D:

The Reporting Persons may, from time to time and at any time: (i) acquire additional Shares and/or other equity, debt, notes, instruments or other securities (collectively, “Securities”) of the Issuer (or its affiliates) in the open market or otherwise; (ii) dispose of any or all of their Securities in the open market or otherwise; or (iii) engage in any hedging or similar transactions with respect to the Securities.

Also, in regards to what "plan" does this group have the 13D reads:

The Reporting Persons intend to have discussions with representatives of the Issuer’s management and board of directors (the “Board”) relating to, among other things, shareholder value, operational failures, performance, management, underperformance relative to its peers and the Reporting Persons’ lack of confidence in management. The Reporting Persons may seek stockholder representation on the Board, as appropriate, including but not limited to through the initiation of a proxy contest at the Issuer’s 2021 annual meeting of stockholders.

Again, I'm very surprised by some of the negative comments about this group. A proxy battle may be coming, changes to the board of directors or management may be coming. However, we just don't know how this will all shake out. We clearly have a group that is disappointed with management. They have filed the appropriate paperwork needed to move a process forward, but it is still too early to know how this will all play out.