Why is the front camera on my iPad Pro m4 13 Inch still blurry after replacement?

The assumption would be that if Apple exchanged the iPad knowing the reason was due to the blurry camera they believed the issue was due to a defect versus software. This is assuming you did your exchange via Apple (you didn’t say if the purchase and exchange was an Apple transaction or if you purchased from an authorized retailer). If Apple feels it is software related and not hardware they would likely inform you that a fix is being worked on and will be released via an update as soon as available. Unless an official announcement is out there that I have missed no one other than Apple will be able to answer your question without it being speculation. With that said, if you haven’t contacted Apple about this and attempted troubleshooting you may want to do this asap so you can make an informed decision on what to do next (particularly if you would want to return for a refund versus waiting to see if the issue can be resolved with a future iPadOS update).