Just to clarify, you can find “Disney Parks” merchandise in Disneyland Paris. Most of these will also be found at WDW and DLR (this is why those items are labelled in French and have “CE” markings, according to EU regulation, even in the US).
There is also a good chunk of merchandise that is unique to DLP, and with the logo “Disneyland Paris”. Sometimes, they are close in look to some other Disney Parks merchandise, sometimes, they are completely unique. This is obviously the case of some “Parisian” merch, such as the “Minnie parisienne” collection, but not only. For example, these Simba ears are marked “DLP”:
In the past, there were few “Disney Parks” merchandise. Over the time, we've got more and more coming in, which was actually nice, because many thought they were actually “nicer” and “more polished” that the “DLP” merchandise. However, in the last few years, DLP quality has stepped up, and this is no longer the case.
One last word, there are some brands that work closely with DLP, similar to Dooney & Bourke in the USA. You can find bags, and fashion, such as for example Eleven Paris:
https://www.shopdisney.fr/marques/disneyland/eleven-paris
Speaking of it,
Shop Disney is a nice website where you can actually browse some of the merchandise sold at DLP. Not everything is there, but nice to browse for some stuff that will be available on site when you'll get here:
https://www.shopdisney.fr/