So reading the Law, whats your response?
Which state/provence ? The link covers multiple, with varying wordings.
All such things can probably equally be said of Britain too. Because all resources under the soil "belongs to the queen". Right ? Yet last I checked, md'ing is WIDESPREAD in Britain. And ... sure... when they find a hoard, they "report it". And if/when they hunt a public land historic archie site (Stonehenge, etc....) they probably need permits. So I think you're reading too much into this.
Also, most of it appears to be for public lands only. So then the same could be said for the USA (Arpa law). Yet laws governing what you find on a federal (or state) land would have no bearing on private land with farmer's permission (why do you think that 99% of British hunters hunt private furrowed field land ?)
Notice the recurring wordings of: for "archaeological purposes" and "archaeological finds" "archaeological discoveries" "archaeological monument", "coin hoards" only. The person who compiled that said himself this is vague. Ok .... sure, fine, you're "only hunting for modern" stuff.

Or "only hunting for individual coins". So what ? And notice too that often time in European countries, coins that are a "mere" 500 yrs. old are not old or significant. Of, fine, how good is your math ?
And notice the author explicitly saying "no ordinance relating to metal detectors exists". So it's just ancillary stuff that *might* apply if you stand on one foot and squint real hard and ask enough bored archies. Well gee, so too can any USA find himself afoul of probably 10 different laws every time he went out. Depending on who he asked and how he asked it . Eg. Lost & found laws, alter/deface laws, cultural heritage, IRS and taxes, etc....
And notice the article writer's conclusion:
" .... Although searching goes on, hardly any object found outside official excavations is shown. Detectorists are far from being ‘persecuted’ in Belgium.... "
As for the section of Postscript 2003: How much you wanna make a bet that any such amendments were coming as a result of md'rs going in and seeking clarifications, definintions, interpretations of prior vague wording, etc.... ?
But Crusader, let's just cut to the chase and assume for the moment that a link such as this means "md'ing is illegal in Belgium". Then how are Belgium hunters doing it ? The OP on this thread is not the first Belgium hunter to come on with show & tell after all .
In this hobby, if you're waiting for red-carpets to be rolled out for you, you're in the wrong hobby.