I would like to understand more why a February release is more plausible now aside from the fact that R&F and GS were released then.
Aspyr needs to release their fix for the Fullscreen and macOS Catalina issues asap. It would be absolutely cruel (it has already been absolutely crue having people wait since September) for them to have Mac users wait almost four more weeks...
A number of people have mentioned that <bug X> needs a fix ASAP - and therefore a patch must be coming any second now - and yet, we haven't had a release (as you point out) in quite a few months. Clearly there is no hotfix bug patch that is driving their release schedule at this point in time.
Next week is MLK here in the US, I suspect that Firaxis will be closed on Monday. Their release process tends to have a full week of build up (some of it behind the scenes), so next week might not be ideal for them. In addition, they have never released Civ VI code in January. (I don’t follow the Xcom release dates, it might be interesting to study that pattern.)
Firaxs has already shown that they take a "slow and steady" approach to their release process. This is probably based on the financial and revenue based outlook of their parent company (2k). In a corporate environment such as that, revenue generating Releases (which a Season Pass would be) tend to be planned out in advance. And they have shown a history to like that revenue spike to hit in mid-February. I don’t know their bookkeeping practices, but predictable patterns of revenue is something that companies like to count on.
In general Nov/Dec/Jan are all screwed up from a corporate point of view. They have too many holidays and large amounts of various vacation times - which leads to an overall reduction in performance and productivity. From a long term planning perspective, it is sometimes easier to write them off, and start fresh in February.
All of the above is 100% conjecture, but based on quite a bit of experience inside the corporate culture of the (non-gaming) Software Development industry.