Let me do some potentially bad AP math (because idk how the game counts the cooldown reduction as) and proper MB math:
Counting procs from after 34 (until 43 since you don't get a proc at 45), you have a max of 4 procs you can get (1 from EA). This makes an average of 3*0.8 + 1 = 3.4 procs. So 3.4/2= 1.7 bloodletters * 110 = 187 potency on average.
AP gives 16% gcd reduction and autoattack cooldown reduction at 4 stacks (which you should have by 34 seconds in it). This puts you your gcd ahead by 0.685 seconds and your autoattack by 0.57 seconds. I am assuming here gcd of 2.5 and autoattack delay of 3 seconds respectively (gets better with lower numbers but we don't put too much sks on brd regardless). Assuming avg gcd potency of 241 and autoattack potency of 80 (I know that's the number people were using for shb due to the trait not buffing autoattack dmg), you average at 210.9 potency.
Idk how bad my AP calculations are but I have heard similar quotes and that even with the buff difference between the two, MB is expected to be 1-2 potency worse per second as a worst case (that full stacked AP). I don't have the numbers they do to make such a calculation so I cannot comfirm that.
But MB was not that much higher in dmg than AP before. These changes just tipped it under it.
Overall minor grievance since they will probably fix that in 6.01.
Personally I wanted the charges to at least mean that MB would have been busier than before. And of course there were the minor questions on whether MB will be the better opener on media tour bard, which was easilly rebuttled by the fact that you don't have the weave spots to be efficient with it.
As I had said in my first post, ShB bard is a job about planning your weave real estate. Currently, there is nothing to worry about during MB (I was personally feeling that it could easily become a boring song and I didn't want 3 stacks of BL even with procs on dots and full procs). Opener looks nice but WM looks way more relaxed afterwards. Apex& Blast looked interesting to optimise in media tour since you would be adjusting their use timings and planning based on kill times etc using the media tour build info, now they are a different 1-2 combo you use on reopener. RF looked like something you would optimise for, now you are kind of forced to have all the codas so it kind of has a long description for no particular reason. To me it looks like they took what bard has to offer as a job and they stripped off all the adjustments you would be making in a heat of rush.