The problem could be if Apple misunderstands what people like about the SE.
When it was first released, the legacy casing was the 5s casing and so it was a great opportunity for them to offer a lower priced/entry level device for a relatively low price by re-purpsoing parts/ideas into an existing older case design.
We all happen to love that case design, and size, of course...
But at this moment in time, the legacy casing is really the 6/6s/7, etc shape/size..and I'm worried Apple is only concerned about the "low entry price" and "re-purposing parts" part of the SE and not the specific form factor and size that we all love it for.
They understand. Why? Because the difference between the SE and the latest iPhone released back then (the 6S) was the screen size/device size itself. The CPU, RAM and other details were identical.