We wouldn't suggest for a second that you should just buy the game until we get a resolution to this, but if you're someone who doesn't own the digital version already and is pondering whether to pick it up, we wanted to bring the GTA+ subscription to your attention - a cheap way to access the game right now along with various other titles.
GTA+, if you haven't come across it, follows in the footsteps of Xbox Game Pass and Ubisoft+ in providing a catalogue of games for a small monthly fee. This one comes in at £6.99 / $7.99 and includes the likes of GTA Online, GTA: The Trilogy - The Definitive Edition, Bully: Scholarship Edition and LA Noire.
It also provides a whole bunch of in-game goodies for GTA Online such as extra money and bonus items:
"Join to claim special GTA Online benefits, access a selection of Rockstar Games titles, and much more — all part of the best way to get the most out of your GTA Online experience."
What's weird is that Red Dead Redemption's new Xbox Series X|S isn't showing as part of the GTA+ library on Xbox right now, but that's how I've personally been playing it so far - it lets me install and play just fine, as you can see below.
It was also advertised by Rockstar Games as being part of the GTA+ library as of December 2nd:
"These new console versions — created in collaboration with Double Eleven and Cast Iron Games — will also be available in the GTA+ Games Library and the PlayStation Plus Game Catalog on December 2."
It's obviously up to you whether you want to check out a bunch of Rockstar Games' titles for a month or just pay to keep Red Dead Redemption permanently - as mentioned, there's a 50% discount on the new version of RDR at launch.
For what it's worth, the average completion time for the main story of Red Dead Redemption on How Long To Beat is 17.5 hours, so if you think you can get that done in a month, by all means go for the cheaper GTA+ option here!