IMPORTANT UPDATE:
I just spoke with the rav from the Kof-K who certifies the Lakewood Matzoh. He said that the Kof-K certifies all the Lakewood Matzoh - both the hand made and the machine made matzos. He informed me that all the matzos sold by Lakewood this year are Yoshon (including all hand made and all machine made).
Lakewood matzoh is Yoshon. This also includes their oat matzohs that may have at times been Chodosh in the past (this year the oat matzos are marked Yoshon on their website).
I had received the same information from Rabbi Herman and so I emailed Lakewood matzoh with this question. I received a response that all of the Lakewood matzohs are Yoshon but are not marked Yoshon. You can order matzohs from Lakewood and find their contact information for any questions at http://lakewoodmatzoh.com/ The Lakewood Shmurah Machine Made matzohs are under the Kof-K and they can be contacted as well about machine made (and perhaps hand made) - https://www.kof-k.org/AboutUs/ContactUs.aspx
According to the person from Lakewood matzoh, since all bakeries are Shemurah from the time of harvest, the only way the flour could be Chodosh is if the bakery didn't care about Yoshon. However, people tend to be careful about Yoshon when it involves the mitzvah of matzoh.
Orders for Shmurah Matzoh from Lakewood Matzoh should be placed by 4 PM on March 21, '18 (eastern time).
I would add that this does not imply that Lakewood Matzoh is the only reliably Yoshon matzoh for Pesach. There are probably a number of other choices, though I would recommend you contact other matzoh companies to determine their Yoshon status.
Also, matzohs that come from Israel with a reliable hashgacha are most likely Yoshon even if they import flour from outside of Israel, though you should check with each hashgacha to confirm whether this is the case with them. Close to two years ago I contacted a number of hashgachas including Badatz Agudas Yisroel, Chasam Sofer, (Badatz) Eidah HaChareidis, Rav Rubin, and Shearis Yisrael (among others) and they said their products are Yoshon.