MP-34S Shadow Panther is post-MP-22 and is also an exclusive (TTMall).
Looking at the list of suffix figures:
https://tfwiki.net/wiki/The_Transfor...ecial_editions
MP-1B Convoy Black Ver. -- e-Hobby exclusive.
MP-8X King Grimlock -- Toy Hobby Market exclusive.
MP-3G Starscream Ghost -- e-Hobby exclusive.
MP-4S Convoy Sleep -- Limited to 2010 pieces, released as part of "future era" promotion in 2010.
MP-09B Black Rodimus Convoy -- e-Hobby exclusive.
MP-12T Tigertrack -- Tokyo Toy Show 2013 exclusive.
MP-11A Acid Storm -- TRU exclusive.
MP-18S Silverstreak-- Tokyo Toy Show 2014 exclusive.
MP-10A Convoy (BAPE ver.) -- A Bathing Ape exclusive.
MP-10 Convoy Mode "Eva" -- Limited to 1,000 pieces.
MP-05G 30th Anniversary Megatron -- Hasbro Asia release (not released in Japan).
MP-11SW -- Originally Chinese release under Hasbro Asia then subsequently TTMall exclusive.
MP-18B Bluestreak -- TTMall.
MP-11T Thundercracker -- TTMall.
MP-10R Convoy (BAPE REDCAMO ver.) -- A Bathing Ape exclusive.
MP-21R Bumble Red Body -- Cybertron Satellite exclusive.
MP-14C Clampdown -- TTMall.
MP-11NR Ramjet -- TTMall.
MP-14+ Alert Anime Color Edition -- TTMall.
MP-25L Loudpedal -- Tokyo Toy Show 2016 exclusive, remaining stock sold off at TTMall.
MP-11NT Thrust -- TTMall.
MP-11ND Dirge -- TTMall.
MP-10K Convoy (BAPE BLACKCAMO ver.) -- A Bathing Ape exclusive.
MP-15/16E Stripes, Nightstalker, Wingthing & Enemy -- TTMall.
MP-711 Convoy (7-Eleven ver.) -- Japanese 7-11 store exclusive.
MP-34S Shadow Panther (Beast Wars) -- TTMall.
MP-17+ Prowl -- TTMall.
The only ones I have question marks over are some of the pluses, as some have been mainline (MP-12+), whereas others have been TTMall exclusives (MP-14+, MP-17+).
The only ones that don't fit in are:
MP-21G Bumble G-2 Version and MP-12G Lambor G-2 Version (possibly because G2 versions are their own thing).
MP-1L Convoy Last Production -- Special edition final use of mold, different shade of red, embossed words on the back, electronic base.
MP-10B Black Convoy, MP-11S Sunstorm -- although the latter was hard to get.