Not sure. I do have my iPad set up to receive SMS messages from my iPhone, but it's rare when the iPad is self turned off, and rarer still when I delete a message before it appears on the iPad. (And on my Mac.)
You'll have to let us know what happened when the iPad is turned back on.
I have an iPhone X and an iPad. They are both linked. If I receive a sms message on my iPhone but my iPad is dead at the time will that message still show up on the iPad when it’s turned on? Will it pop up as a new message? I deleted the message from my iPhone but I don’t have the iPad with me and don’t want someone to see the message if they charge the iPad.
The iPad has been dead for about a week. I had iMessages turned off on my iPhone I believe when I got the 2 messages.