Not universally true. You want to pump the number of times necessary for you to get sufficient milk to cover the baby's intake while you're at work. For some moms, that means pumping as many times a their baby eats, for others it means pumping more or less often. So you may not be able to drop that 10 am pump. You may even need to pick up a pumping session.
one is supposed to pump the number of times baby gets bottle
This may have nothing to do with supply. Many babies get fussy at the breast when they get bottles because getting milk from the breast requires more skill and effort than getting milk from a bottle. A bottle requires almost no effort at all. And many babies start night-waking and night nursing when mom goes back to work because they miss her. Also, it's textbook normal for babies to go through phases of increased night waking/nursing when they are teething or mastering new developmental milestones, and at 6.5 months your baby is probably doing both.
I want to drop the 10 am pump. Because I feel like there is no more milk after I get home the rest of the day. Baby is frustrated at the breast with not much milk and waking up at night hungry which she hadn't before I went back to work!
If only it worked this way! The truth is that most moms find that stress doesn't impact supply very much, if at all. Which is a good thing, because otherwise our species would never have made it out of the Stone Age. No matter how stressed we modern moms feel, it's nothing to what our ancestors experienced! Sabretooth tigers, the Bubonic Plague, war, famine- now that is stress. And yet moms somehow managed- and continue to manage- to nurse their babies through stressful times.
On the other hand my hubby says less stress from running behind at work from pumping at 10 am might allow more milk supply.
ETA: Your baby is taking fairly large bottles. How much is he drinking while you're at work?
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"