I don't see how that would be a problem? The update on the initial post would only be seen by new readers, not people that had been following the thread from the start. And new readers will probably take the time to skim through the thread to see other user's comments.
Also, what you are suggesting would break the idea of following the topic, wouldn't it? If the original post gets edited the people that are following the thread won't get notified if I'm right.
Say you found a software from the software forum that you want and the topic has tons of pages, then you probably won't read all the pages. (e.g. Speckie has 20 pages). So chances are, you download it from the first page which probably contains an older version because the first post hasn't been updated yet as the moderator is not online.
The OP could easily post "See first post for details on the update." meaning the follow system is still in use.
which is why i say it would be something you'd have to sign up for (possibly posting a link to your project as well) and be granted permission to do. and it would only have effect in the Software Discussion & Support Forum & only in Threads that you started
i can't think of too many ways to abuse that & if someone does it wouldn't be too hard to take care of that person
I agree since people would have to sign up for it, I doubt they would abuse it.