Your subscriptions should be good for your ACCOUNT, not your individual devices. As long as you link the new Rokus to the same Roku account you should be good to go.
Note that you may need to authenticate each of the new devices with each of the subscribed channels so the channel knows your device belongs to your account with them.
- Roku Streaming Stick +, 3810X, Ser YH0059427035, wifi - Samsung UN55ES6100
- Roku Streaming Stick, 3600X, Ser 5S56D8240827, wifi - JVC EM37T
- TCL Roku TV 43S425/C107X, Ser X000001R60KV, wifi