I can imagine if Seagal is already a 7th Dan and he's a part-time police officer, amatuer musician, film & tv star then his motivation or time to dedicate to Aikido nowadays must be less. Aikido played such a big part of his life that I don't blame him if he wants to pursue other arts. However, as Aikido still plays a big part in his fight scenes and choreography then I would assume he still practises.
Exactly what i mean. His speed and skill in the true justice series indicates he is still doing it.