Reticulum = software (protocol level)
Meshtastic = whole stack inc. hardware
I accidentally replied to your linked note and not here.
No, Meshtastic isn't the hardware.
Both these things are more or less at the same level within the stack, but have different goals, and Reticulum will work on the same kind of low power LoRa hardware as Meshtastic, but Reticulum can also can use other network bearers like WIFI, Ethernet, etc.
Here's an interesting brief write up (not mine) that does a comparison.
https://blog.erethon.com/blog/2024/01/31/comparing-reticulum-and-meshtastic/
Discussion
There is no Meshtastic dedicated hardware.
You can't deploy reticulum over Meshtastic.
People have packaged hardware and software together specifically for Meshtastic, but the same is true for Reticulum too.
You can buy a premade Reticulum rNode like this:
https://unsigned.io/shop/product/handheld-rnode/
which would be about equivalent to buying a pre-built Meshtastic powered device something like this:
https://muzi.works/products/r1
but these are both generic LoRa hardware running the relevant software stacks for either system and a swanky 3D printed case wrapped around them.