re: Am I correct in understanding that the SEC-Network will only be on AT&T Uverse?

Yes, I cut the proverbial "cable cord" a couple of years ago. My neighbor has Uverse and gave me his logon info. I've got HBO and ESPN using his stuff and subscribe to Netflix, Hulu and Amazon Prime on XBOX. With my subs and Uverse internet bill, I pay a grand total of about $65 a month for everything.