Reworked Yorick is not weak, but old version was stronger (so long as you didn't waste time buying mana items, opting for better mana efficiency of AD or Trinity rush). Now though, he works much the same way, opt for AD and only go for trades when you have several graves available. Maiden is a bit more clunky and unresponsive than even old Yorick ult, but with a trade in damage and utility. Seriously they are basically the same design with shifts in power.
Now, all that being said, I think there is too much power in his new Ult, and too little in his situationally very powerful wall. His kit lacks consistent graves production outside of landing multiple Last Rites, leading him to be starved of early game power, meaning he can only ever start to go for trades around luv 2 or 3 at the earliest. Then he heavily power spikes at 6, 9, 11, and 16. The three outs and when he can finish maxing his primary damage skill (either Q or E depending on what you like better. . . For me it is E).
You can play him like old Yorick maxing E and trying to land it whenever they go to last hit, whittling them away and using the movespeed boost to run in and land a Q to build graves or summon walkers and use the slow on them to land a wall for some good trading or an all in.
To really fix him though shift the summoning of walkers out of his ultimate and into graves production when his wall decays or is destroyed. That will make it useful even against enemies with dashes that can simply ignore it, while simultaneously making him less reliant on his ult to do anything.