I've been blessed to have sold a Lenten series to CPH for publication in _Concordia Pulpit Resources_ as well as a couple of sermon studies/full sermons for that periodical. I was honestly honored and humbled when pastors from across the country called and emailed me questions about the series. (For some odd reason, CPR didn't include the Maundy Thursday and Good Friday sermons from the series but said they were available from me. I got a lot of requests for them. I also sent them all of the original Word docs to make it easier for the pastors to write their sermons.)
But those are sermons that are published with the understanding that others will be making use of them. In this case, it appears that the new SBC president was lifting sermons that he found elsewhere and was preaching them as his own. That, I think, is much more troublesome. About twenty or so years ago, there was a pastor near me, who had the same first name, who took several newsletter articles that I wrote, covered over our church's heading, and republished them as his own. I found that very irritating and unethical. I finally took to printing my article with colored paper to put a stop to it.
Interesting topic to discuss!