Unless you have a specific need for a suspension fork, most will recommend a rigid fork -- especially if the bike was designed for a rigid fork. A suspension fork is physically taller (the fork crown to axle distance is longer) and this will increase the head tube height of the bike, which will change the geometry that we just talked about above. What happens when the head tube is raised? Yes -- the angle also decreases (becomes shallower). If the tire size and offset are similar to before, a shallower head tube angle will generally increase trail and also will increase flop (the tendency for the handlebars to want to fall one way or the other by themselves).
Depending on how you ride, more trail may be desireable or not. I personally prefer bikes with LESS trail because of how and where I ride. I have a '70 Peugeot mixte bike which has only about 45mm of trail. It's a very pleasant bike to ride at slower speeds because there's almost no flop and it tracks very straight. But at higher speeds, it's less stable and much more sensitive to steering input. I once bought a bike that had nearly 100mm of trail and I hated it. It was probably the bees knees bombing down a dirt track at 25-30 mph, but that's not how I ride. The large trail and flop it had in its geometry make it rather laborious to ride at slower speeds (it kept wanting to turn on its own), and felt rather "weird" to ride. I didn't like it and took it back to the shop a few days after I bought it. Some may have liked it -- it's very much personal taste.