According to the Independent:

Labour Party members will have the opportunity to force Jeremy Corbyn to commit fully to a fresh Brexit referendum, after the party bowed to pressure to stage a consultation.
The grassroots survey will be launched next month and conclude by early August, The Independent can reveal – paving the way for the policy shift as a new hardline Conservative prime minister arrives in No 10, supporters believe.

We will see if this actually happens - so far only the Independent seems to be claiming it will - and we will see how the results are handled come the conference. Calling for a referendum, for example, does not say what the question on such a referendum would be. Combine this with the rising suspicion that a Johnson PM would be forced into a general election and how the two strands combine will be very significant: will Labour commit to a referendum on any Brexit deal as part of its manifesto, for example?