The effect of the change in suspension gepmetry is the same regardless of the size of the tires because the end result is still the same. To simplify, the angle of the suspension arms while the vehicle is at rest has changed relative to the chassis. This also changes the angle of the knuckles (or spindles) to both the chassis (camber) and to the steering box (toe) thus requiring the alignment be reset. This is why if you talk to the perosn performing the alignment they should refer to the measurements of camber, caster, and toe as static measurements because each changes as the suspension moves thru it's normal range.
If you're simply adjusting the preload to reset those angles to the way they were front the factory (to compensate for suspension sag) then you have essentially made zero net change from the last alignment and (in theory) an alignment would not be necessary. For anyone who offroads or has bumped a curb, you will probably find that an alignment is necessary regardless.
2004 Dodge RAM 1500 QC 4x4
1988 Jeep YJ
Custom front and rear 4-link, TBar Fab bumpers, tire carrier and rock sliders, Warn 9.5ti with 125' of 5/16" Amsteel Blue, TJ coil springs, 35" Goodyear MT/Rs on RockCrawler wheels, ProComp swaybar disconnects, Uniden PC78 Elite CB, 7" fender flares