It can, yes, but will it?

A lot of that depends on how Nintendo's subtle shift in strategy with 3DS plays out. The combination of releases we're seeing in the short-term points to an attempt to rediscover the low-income family market that allowed GBA to sell alongside DS into 2007/08 in North America and some of the 'Touch' generations vibe that powered DS to an astonishing 120 million units across North America and Europe. There are clear signs that 3DS - which has outsold GBA in Japan - has clearly not found the Western market that powered DS and, less widely acknowledged, GBA to greater success. GBA sold 63 million across Europe and North America, for example, with ~40 million of those sales coming in North America. By way of comparison, 3DS has sold  a little over half that in North America. We can say, clearly, that 3DS will out-perform GBA in Europe and Japan, but is currently some way short of that in the North American market, and finding some of that Western market for GBA/DS will decide how long Nintendo keep 3DS on the market, and whether or not it can ultimately outsell GBA.

Clearly Nintendo are pushing for that younger, lower income market, with New 2DS XL and 2DS more broadly increasingly becoming the focus for the 3DS family. On top of that, we're seeing a mixture of child/family orientated titles and riffs on the 'Touch' generations line-up coming to market (moreso than usual): Hey Pikmin!, Ever Oasis, Devillish Brain Training (5 years after it came out in Japan!), Cooking Mama, Miitopia. Nintendo are even localising the kid-orientated Monster Hunter Stories, which Capcom considered a disappointment sales-wise in Japan, which is an interesting move. We'll likely see a degree of cross-platform software support into 2018 (Switch/3DS), and 3DS still has room to move on price, so there are ways for Nintendo to shift more units. Additionally, we might see legacy titles sell strongly through hardware bundles, or through the success of smartphone titles (Animal Crossing mobile may trigger a revival of Animal Crossing sales on 3DS, for example). 

3DS needs at least three years of meaningful sales to beat GBA. If we assume Nintendo hit their current FY target, then 3DS is at 72 million in March 2018, and needs to ship another 9 million or so before being discontinued to beat GBA. I think it's more likely 3DS will end up in a very similar ball-park to GBA. If Nintendo allow 3DS to trickle along, then matching GBA isn't unreasonable, say they ship 4 million in the financial year ending April 2019 (76m), then 3 million (79m), then 1.5 million (80.5m), then 500,000 (81m), for example. While I think 3DS can match GBA, I think out-selling it (certainly by any clear margin) is far less likely. That being said, Nintendo may yet find there's a sizeable lower-income market waiting for 3DS to come down in price, and that might shift a few million more units.