No, everything will stay the same! All current SmartLess Mobile customers will still have the exact same service and plan (and the same pricing too!). Because Noble Mobile is also on the T-Mobile 5G network, your service will be automatically transferred on October 28 - no need for a new SIM or any update (though you may still see "SmartLess" as your mobile carrier - your service is still secure and active with Noble!).
One additional bonus: on Noble Mobile, everyone enjoys free roaming in Canada and Mexico!
Note: You need to save any voicemails you want to keep before October 28, as older voicemails will not transfer over.