Those who have purchased the specified vehicles prior to the stated time will still have them in the garage.
The reason for the removal is the introduction of the French Tech Tree. Historically the PzKpfw 38H735 (F) and PzKpfw B2 740(F) were French tanks, and they were placed in the German Tech Tree as captured vehicles.
If you would like to own the PzKpfw 38H735 (F) or PzKpfw B2 740 (F), you still have time to do it prior to the February 13th restart. In the future it may also be possible to obtain the above-mentioned vehicles through special offers, which will be announced in advance.