Remove report junk when deleting text messages

You can't. This is part of the new interface in iOS 16.

Feel free to let Apple know your thoughts via this link --> Feedback - iPhone - Apple

It's actually a useful (albeit extra step process) feature. As people have complained about junk messages for a long time and Apple listened and has added a simpler way to report messages as junk. Ultimately, this will help us all see less junk messages. But yes, we do need to report it and that's why it was added.

It would be better if you can please re-post with a screenshot, in order to understand the phenomenon better. Images/pictures speak louder than words. 

Please understand this is a public forum: While attaching a Screenshot, do not provide any personal credentials, such as IP address, Card detail, email id, apple id, IMEI number, Serial Number, Phone number, Order ID, if you are sharing a map ensure your location is not identifiable, etc.

With the limited information that you have provided, It is hard to even guess the problems faced by you. 

You may get faster and better responses to your query by --> Writing an effective Apple Support Commun… - Apple ...

Please re-post with detail so that someone else can help.

Please follow the process laid out here.

Delete a conversation

1. In the Messages list, swipe left on the conversation.
2. Tap Delete.

Delete messages on iPhone - Apple Support (AE)

That's not addressing what the OP is asking about. In iOS 16, when you do what you suggest and tap Delete, another box opens with the opportunity to Report Junk or Don't Report Junk. The OP doesn't want to have to take this step. It's a new feature.

See the pics below which is self explnatory

You're welcome.