TLDR; Bard shouts aren't of enough value to go on your bar.
An aoe stun is probably the best, but the 3sec duration means you can get one mez off in the window they're stunned. Also helps with interrupt casts, but the CD makes its not ideal for this situation.. but at the very least more use cases makes it more likely to get a spot on the bard spellbar.
An insta mez that takes half your bard career just to give you time to properly mez the thing before it wears off. Its just a straight downgrade over the aoe stun. I used this very early in my bard career for when something resisted mez it gave me a second chance of landing a mez before it broke, but as the theme of this post will continue... I quickly found more important songs I needed/wanted on the bar. The most value this has is a very long CD kick if somehow nobody in the group can interrupt.. usually just rely on mez spam to catch any spell being cast in those scenarios.
The fear I just don't understand why it exists in its current state.. EQ bard had a spammable AoE fear it was a double edged sword (chaotic CC option risking social agro'ing more or solo tool) so it saw very little use so I'm not sure why MNM bard its been amputated so badly. That said.. if it were AoE would be far more useful then the stun giving you time to mez 2 things (possibly 3 if a target mostly runs away from you). Making this AoE would really help with pulls that go wrong to buy that extra time bard needs to get control of multiple things.. it'd be a clearly worse option then INQ and ENC aoe stuns, but give bard atleast something to prevent a healer from getting whacked on for 9 seconds to mez 3 things. Though this still won't help with undead who are immune to fear and our best option atm is charm 1 thing and have it attack a couple other things till we have time to mez it, but that also doesn't work on undead now.. maybe this could be changed to a fear and undead fear with the addition of AoE too? It just feels like it should be a song rather then a shout.
The 'nuke' line.. has always had this weird issue where at lvl 20 the mana cost spikes making it a huge mana drain and basically always forcing you to suddenly start using the lower level variants. (dmg numbers @lvl39; 3mana 12-23 dmg, 10mana 18-30dmg, 50mana 30-48dmg, 70mana 54-81). So it just scales in the wrong direction dmg:mana ratio wise suddenly at the lvl 20 song 'Cacophonic Vocalization) making it the only spell line in the game that gets worse when 'upgraded'. The updated dot lines completely dwarf these nukes in value on the bar and I'm sure will clearly get updated at some point in hopefully the near future.
Also there is an issue with all the shouts sharing a CD means your nuke line suddenly will get a 90sec CD because you had to use your emergency/utility shout making all the longer CD shouts even more undesirable. At the very least it feels like the nuke line should have a seperate CD from all the longer CD ones. And 'repel' too. which I didn't even bother to mention in the list of shouts because its so niche I've never had a reason to bother with it.. feels like a song added to deal with our threat issue from having to spam mez when in reality mez should just have a threat reduction component in it like ENC. And either way it doesn't matter because taunt will take all that agro anyway or we just charm something to reset its threat to 1.
Getting off topic.. shout! I was really hoping this was getting an overhaul with the rework and hoping it still will at some point. Its a very cool system that gives the bard the ability to instantly react to a situation that was sorely lacking with everything on a 3sec cast time. That sadly just doesn't feel worth the space on your bar 99% of the time because of limited space making rare situational cases rarely worth the limited slots, horribly long CD's, and just weak effects.
We need shouts to be our quick response to react to things ie 'silence' a target preventing them from casting for a duration. Give it no dmg and slightly longer CD then kick and it might see some use for those rare scenarios where you have no interrupter in the group or for solo.