Hi teatime45,
Yes - delivery dates for most physical products have been impacted by the Covid-19 virus. Even the OG2021 (which is the most recent version of the Official Guide) had it's anticipated shipping date pushed back almost a month (currently set for early June). Thankfully, there are lots of non-print study materials that you can use during your studies. In addition, while the OG books are great sources for practice questions, but they're not designed to teach you Tactics, patterns or the little 'secrets' behind the GMAT - for those, you'll need Course-oriented materials. To that end, you might want to work on the OG a little later on in your studies (depending on where you are in your studies right now).
Before I can offer you any additional advice for your studies, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) How long have you studied? How many hours do you typically study each week?
2) What study materials have you used so far?
3) On what dates did you take EACH of your CATs/mocks and how did you score on EACH (including the Quant and Verbal Scaled Scores for EACH)?
Goals:
4) What is your overall goal score?
5) When are you planning to take the GMAT?
6) When are you planning to apply to Business School and what Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich