I don't think is a success, nor a failure yet. Sales itself is not what will make the 1x a success its changing the perception of the xbox. I don't think it did. Ps4 is still the #1 in everyone's mind mainly because the games coming to the ps4 has people talking. The only talk we hear positive of the 1x is that it is slightly better than the pro in games available everywhere.
I highly doubt any big unannounced games get dropped before E3, so it will take until after E3 to truly say if it failed. We already know it did not succeed, but its not a failure yet. So like always, we will see the sales of the xbox family almost disappeared for almost 6 months.
And with what you said there, perhaps Microsoft is being tight-lipped on any upcoming titles. We know of Sea of Thieves on March 20th. But then really nothing else. So perhaps E3 will be big for Microsoft to announce games coming out in the fall like their usual bread and butter. But with Microsoft being silent with reveals and release dates that's probably is why PlayStation hasn't officially announced release dates either. Yet they have titles to reveal empty slots. We've Got Monster Hunter World (multiplatform) which is going to go just bonkers on PS4 especially in Japan in January. Also in January PSVR's The Inpatient. Shadow of the Collosus Remake and Secret of Mana in February. Ni No Kuni 2 in March. This leaves April through December (8 months) to plan dates best for hopefully; God of War, Detroit, Spiderman, Days Gone, Dreams and Concrete Genie. 6 titles along with 3rd party's; Ace Combat, Anthem, Biohumant, Code Vein, Dark Siders 3, Dragon Quest XI, Kingdom Hearts 3 and Far Cry 5 just to make this book lengthy..... sorry. I think we're all just waiting for Microsoft's next play.