I personally disagree with this idea, as I feel that, as commandblockguy stated, this would make it difficult for new users to quickly get an answer to a question, or to receive feedback and encouragement on their programming projects.
I can support this with my own experience, as well--I joined because I saw that there was a "Cemetech Contest" going on, and I wanted to participate in it (this was CC22). The first thing that I did with my new account was make a
thread for my contest submission. I imagine most true new users join to make posts like this: the only real point in having an account here is to participate in the forum and/or SAX/IRC, but I doubt that second option is particularly appealing to truly new users, as it's less popular than Discord among the youth.
So my final conclusion is, spam is a component of the forum that won't soon disappear. It may even make moderation more difficult, as instead of having the spam member join, make the spam post, and be quickly deleted, these members will be forced to lie dormant until the post is made, which might unnecessarily complicate things. I'd advocate for promoting more trusted members to moderator to solve the problem instead, as I feel like this solution wouldn't be an effective one.