No. Chat Merge never sends a message itself. For each row it opens a chat with the person’s number and your message already filled in, and you press Send in WhatsApp. You see every message before it goes out, and nothing is sent until you press Send.
What Open next chat does #
Open next chat only opens the next chat. It jumps to the next row that has a valid number and no status and opens that chat for you to send. It does not press Send for you.
What the status column means #
The Chat Merge status column records that you opened a chat for a row. It cannot tell whether you then pressed Send in WhatsApp.
If you want messages sent for you #
In Excel on Windows, Chat Merge can hand your contacts and message to SendCommander, a separate paid Windows app from the same publisher, which can send the messages itself. SendCommander shows them for your review first and sends nothing until you confirm there. The pane card for this is called Send many at once with SendCommander. See Send automatically with SendCommander. Chat Merge is complete without it.