Thats an older/slower modem/router combo device you have. They’ll probabably only provide you a modem free. Its more up to you if you’d like to stick with what you have or upgrade to a better router 

According to Spectrum/Charter, while they have previously approved this gateway, they will no longer facilitate new activations for this model. We would recommend upgrading your gateway to a DOCSIS 3.1 model.

Additionally, you may want to check with Spectrum to see if they still provision DOCSIS 3.0 in your area. If so, you can continue using this model for now, but we would still suggest considering an upgrade to a DOCSIS 3.1 gateway.

Thanks for all your advice.