Thanks for adding this 👍, NVDA reads rows and column headers with without the week number being specified a header, you end with 8 columns and 7 weekday headers and the reading is skewed when numbers are active.

Okay, something bothers me about this one. It's not quite right describing it as a list. Some AT do read the list when entering and "List with 7 items" or "4 out of 7" are not really descriptive of how this component behaves. It's and endless scroll.. or spin ☺️
So quite a lot like this: https://www.w3.org/TR/wai-aria-practices/examples/spinbutton/datepicker-spinbuttons.html
I'd love to say you can get away with reverting these back to div/span and binding the role in the igxCalendarYear directive in a similar way as it's done for the tabindex:

    @HostBinding('attr.role')
    public get role(): string {
        return this.isCurrentYear ? 'spinbutton' : null;
    }

    @HostBinding('attr.aria-valuenow')
    public get valuenow(): number {
        return this.isCurrentYear ? this.date.getFullYear() : null;
    }

This works for the most part, except when navigating the year list items actually shift positions in the DOM for whatever reason - that has the unfortunate effect of announcing the spin button every time since you focus a new element each time :/
PS: Also NVDA insists on navigating lists on its own (haven't found the setting to stop that) and thus swallows the key up/down events and the list never scrolls for me, so that'll fix that as well.

If this proves too complicated for now I'm down with logging an additional issue to improve the years picker/view.