I am excited to say that today, the Inbox team has started rolling out the ability for users to select multiple emails with the use of the shift key. Simply put, select the first email you want, then scroll to the last email you want selected, hold the shift key, and select the last email. All of the emails in between will now be selected for you to do whatever you want with. This shift select works in every label/bundle including spam, trash, system generated and user generated. It should be noted also that keyboard shortcuts work here as well using Shift+X. See the video below
You can even move all of the messages selected to any label/bundle you want, however you will not be prompted with the "always do this" message as the select multiple will have various senders.