As the title says, I think that a no shield tag should be added to the Bamboo Spear and Ashwood Pike. Why?
The huscarl + ashwood/bamboo combo makes for a support character who can "poke" as effectively as someone with a longspear, but can survive a 1v1 or 1v2 nearly indefinitely. There are numerous "offensive" shields that can be used, plate covered and plate shields are also annoying, but the huscarl is the most annoying because it gives a ton of coverage making it hard to actually land any hits, in addition to its toughness. Lengthwise, an ashwood pike used with a shield has 227 length with the 1h stab bonus (+61 according to shik), and a bamboo spear has 261, compared to the longspear's 264 with 2h polearm stab bonus (+19 last i heard).
In addition to this, the ashwood and bamboo spear do not have the "unbalanced" trait, are cheaper (ashwood is 1k less, bamboo 2k less), are faster (ashwood 93, bamboo 90, long spear 81), and in the case of the ashwood, higher damaging (31p, longspear 26p). All this adds up to poor internal balance of support polearms.
Compare a Bamboo Spear + Huscarl to a Longspear. In trade for an autoblock (shield), 9 speed, and no unbalanced malus, you lose 1 damage and 3 length. If you were going to go pure support and didn't want to use a pike (terrible in every aspect except for length, and given that the bamboo spear isn't all that much shorter I don't see much of a reason to use a pike as pure support) there is basically no reason to use a long spear over a BS/SH combo.
The Ashwood Pike is similarly better than a longspear, except you lose 37 length and gain 12 speed and 6 damage. In addition to this it allows you to hold your own in a 1v1 situation due to the speed and the odd "activation" timing of polearm stabbing. It's also nearly the same as the awlpike which also recently had a "no shield" tag added.
Lastly, the latest balance patch was clearly intended to reduce the ability of support to function once in close combat - Nerfs to speed, unbalanced tags, no overhand on the longspear, removed awlpike+shield, 3 slots - and the ashwood/bamboo+shield combo still falls into the category of "support that is hard to kill up close".
I think the bamboo spear is still plenty viable if it were made no-shield because of its speed, cheapness and good length, however if ashwood pike were made no-shield I think it would need buffing to remain useful, maybe add sideswings to make it a longer, cheaper alternative to a warspear.