That is the normal practice for all business from hotels to building material suppliers - USD at BNA rate on day of payment.I think this is an anecdote of a single person being ripped off. Unfortunately for them.
We have a hotel booked in Misiones next month and the price was quoted in dollars which is very normal (the Alvear hotel group does this as a standard practice for example, for all guests - citizens and foreigners alike). I wrote our hotel to ask and received the following response —
“Las tarifas en USD se convierten al dólar oficial BNA venta del día del pago.”
The new problem is since Friday when some hotels falsely think they should be charging at the MEP rate because they don't understand the concept.
Just be aware. The hotel I booked has 4 or 5 locations across CABA.