I think Marquee will only be used for the Chicago RSN carrying the Cubs. It's thought that they may rename all those Fox Sports RSNs to "Diamond Sports," e.g. Diamond Sports South. This is because Sinclair formed a subsidiary called Diamond Sports Group, LLC to serve as the owner of those RSNs that they recently bought from Disney (which in turn had acquired them from Fox).
As for Stadium, that's the name of Sinclair's nationwide odds-and-ends sports network. They carry it as a free subchannel on many of their local OTA stations. Here in Nashville, it's on channel WNAB 58.2. They also include it on free streaming platforms, like their own STIRR app, Pluto TV, Xumo, etc. You can also find it in certain cable TV packages.
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