Just sharing. I'm new user using 30mbps on 30 days free trial package. After a month, contact live chat asking special 300mbps package. They raise report to sales dept.

2 days later, got call offer loyalty package 300mbps RM129 + Deco M9 Plus RM30. Agree with the offer, then 2 days later speed increased.

I just sold the mesh wifi as I'm staying single storey house only. Basically paying rm129 for 300mbps which i consider good deal for new user.

300Mbps for RM129? Bloody TMNut 

Since you are Digi postpaid user, I would say the offer is good for you. Yes Digi runs on TM's infra, just like Maxis and Celcom. I believe the offer is to bring their users to consolidate their line on the same telco.
All of this  is just how they do their marketting. If you give cheap postpaid, people may just sign up for the postpaid, but if you give cheap fibre to postpaid users, people may consider to bundle together their postpaid line and home fibre.
Keep us updated.
From 30mbps to 300mbps can get M9.
Since you are paying RM159 for the same speed with TV pack, I think you are getting a better deal than the others because for the same price they are paying, there is no Unifi TV.
I think you should consider to get your own mesh. Try to find the one with tri-band if you are gonna use wireless as backhaul, or find ways to use wired backhaul for better Wifi speed.