A lot of us suffer from DP ( dawn phenomenom). That means our bgs tend to be higher in the morning anyway. I've done experiments with coffee and without it. I find it doesn't matter I still get a small spike in the morning. I even did an all day fast once and my bgs continued to rise until about 2 pm before starting to fall. There are a few who may be super sensitive and get a huge spike and for those they should avoid coffee or bolus for it with insulin.
I don't get any BG rise from coffee and I sometimes drink 3 or 4 cups in the mornings. Some people say they get a rise from coffee, tea, diet soda or anything else that has caffeine in it. I do not but it would not hurt to test this for yourself. The only way you know is to test.
Personally I enjoy 2 cups of coffee everyday (well most days). If it's going to really spike you, then you may want to keep away from it. I use a dash of milk myself and I'm fine. Others here I know use cream instead of milk as it has higher fat content. If you like your coffee, you will find a way to still enjoy it I reckon.