Admiral Rickover was a smart dude. But none of these points are applicable here. This development here is about fusion, not fission, those who are pursuing it are not amateurs at all, they are MIT people and they are not shy to pick up a wrench and use it in a lab. One by one, the points made by Rickover against his adversaries are not relevant here:

1. It is simple: no, nobody says here that fusion is simple.

2. It is small: well, this one is small compared to ITER, but nobody's saying it's small in an absolute sense.

3. It is cheap: sure, compared to the billions and billions poured into ITER, this is dirt, dirt cheap, but still, they have secured $200MM so far, and they will need more money until they build an actual reactor.

4. It is light: really not applicable here, since nobody's thinking of putting these reactors in submarines (which is what Rickover was really talking about).

5. It can be built very quickly: sure, the time horizon is less than the perpetual 30 years of the old fusion reactor proposals, but it's not going to be "very quick",

6. It is very flexible in purpose: no, for the time being, something that just works is fine, nobody cares about flexibility,

7. Very little development is required, it will use mostly off-the-shelf components: nope, there will be plenty of very custom made components developed for just this purpose, and lots and lots of development are required.

8. The reactor is in the study phase. it is not being built now: it is both in the study phase and being built.

In the end, what was Rickover's agenda: some people were competing with him for government funding for nuclear reactor R&D in general, and for naval nuclear reactors in particular. All those people were a nuisance to him, he had to go and plead for funds again and again, so he decided to write this letter to put this thing to rest once and for all. He managed.

But here it's fusion. Commonwealth Fusion is privately funded, they are not looking for government funding, and they are not making inflated representations to the public. They are actually keeping a low profile in general. The message of this article is simply "this time there is a glint of hope", nothing more.