We should probably start making a distinction between Dem candidates and the DNC. You probably mean the latter. As for the Dem candidates, that’s far less certain and here’s why.

Outside a minority running as establishment candidates (mostly incumbents) the DNC is struggling to maintain influence. Even the non-DSA wins have shifted heavily to local issues in their campaigns and distanced themselves from DNC priorities. Mainly this is because DSA has been on a big winning streak with that strategy, and D candidates want to win. But it’s also because the DNC blew a huge amount of its warchest on several key primaries that they lost.

In other words, the DNC has not only tried and repeatedly failed to secure wins for its candidates (a bad losing streak that doesn’t inspire confidence) but now the DNC has even less money that it might have otherwise proffered to keep candidates in line. Of the funds remaining, much of it has been marked toxic by candidates in key races, meaning even if the DNC offered it for free they couldn’t accept it.

Candidates are the ones campaigning. They have the mic and can choose whether to share it with the convention leadership by towing party lines. Since the DNC has less to offer this year, and in many races might hurt more than help, there may be far less mic sharing than usual.