Sorry to chime in a bit late, but had a couple thoughts here.
That’s an interesting reading of the rules, and one I had not fully considered, and I wonder if HBG did not as well when writing them. The rule reads (as in not with the expansion):
Dutch Territories: When the Axis declares war on the Netherlands, place a British roundel
on all Dutch territories. Britain receives all income from these once at war. The British player
may, when collecting income distribute the income from Dutch territories between Great
Britain, the Far East Command and the ANZAC as he sees fit.
By that reading, just on it’s face, the UK, FEC, ANZAC do not automatically enter the war once the Netherlands is attacked. They all get increases, sure, but they do not automatically enter the war. So it’s a bit misleading to say the UK is missing out on all that money, when they might not be getting it right away anyways.
But I see what you’re saying. If you make the adjustment of placing British roundels on all Dutch territory immediately after war is declared, then that could be construed as war on the British.
My gut tells me that what HBG meant with this was that they are still Neutral Dutch, but are now British controlled until alignment can happen once the UK is also at war. Regardless, it’s another example of really needing to polish the rule set to be waaaaay more clear/less contradictory. But yeah, I agree with @GeneralHandGrenade that the interpretation is as he lays out. But again, I’d say very astute reading on your part for the technicality!