I've bought London-Brussels tickets on Eurostar for travel in 8 weeks. My partner and I will arrive mid afternoon and will travel the next day to Amsterdam. Is it my understanding that we can ride to Antwerp (valid on Thalys) within 24hr of arriving in Brussels, and then go continue on the same Thalys train to Amsterdam? Not much of a savings but it's €8 each.

I haven't found anything on the Eurostar website that says anything about this feature.