I assume that low production specialty block manufacturers do not have the resources/budget to construct a block with integrated sleeves, instead of a slide-in or bonded type.
Honda's example;
http://dwolsten.tripod.com/articles/jan96a.html
I seem to recall while watching a production video on the (al.) ford romeo block, that a hard alloy skin is formed on the piston cylinder walls, and forms some type of metallurgical bond between the dissimilar metals.
I stand to be corrected, because I cannot remember if it was this ford block or not.
2011 shelby engine;
"The new engine uses state-of-the-art Plasma Transferred Wire Arc (PTWA) liner coating, a process that applies a 150-micron composite coating that contains nanoparticles on the internal surfaces of engine cylinder bores, replacing cast-iron liners typically used in aluminum engine blocks. The Intellectual Property Owners Education Foundation honored the inventors of the Ford-patented PTWA technology with the 2009 National Inventor of the Year Award."