I do. D&D players have been trained to expect it. It started in the 90s with 2nd edition - the assumption that you would be getting regular expansions to the game via splatbooks, or settings, or just rules expansions. That TSR (and later Wizards) would be putting out at least one book a month, probably more. That assumption continued into 3rd edition and to a large degree became even more expected because in 2nd edition most of the character options that expansions would add were for new characters you were going to make while in 3rd edition the expansions were new things like Prestige Classes and Feats that you could add to your current character. 4th edition continued that trend to the point that they changed the writing focus and design focus to make it very obvious to everyone exactly how expansions would plug in to the design.
The 5th edition release isn't just a return to a simpler version of D&D, it's a return to a different set of publishing expectations. Expectations that nobody has had for the game's release schedule really since the early to mid 80s. In that time period TSR mostly released adventures and other DM-focused material for D&D - where you did get player expansions it was generally in the form of entirely new classes or the occasional subsystem (like proficiencies) and mixed in with DM material (as in the original expansions like Greyhawk and Blackmoor and then later expansions like Unearthed Arcana and the Dungeoneers Survival Guide). That early-to-mid 80s pattern seems to be what Wizards is going for right now and while I personally am a bigger fan of the "fewer releases, fewer rules expansions" model, it's completely understandable that for folks who think that a "typical" D&D release schedule looks more like the 90s or the early 2000s it would be really jarring to not see major rules expansions for years.