Yes, the idea is simply to increase ROI of dividends. There is no guarantee the price of the coin will increase although it seems logical to assume that higher dividends will lead to a higher price. That additional 25BTc would have to outperform the other 75 BTC invested by a huge amount to match the +50% ROI we would get under the buy and burn plan.
From purely a dividend perspective... perhaps.
From a coin valuation perspective however, all that 25 btc would need to do is increase the price of the coin on an exchange by a somewhat small amount.
Ex. 25 btc invested in decentralized marketplace + anonymity.
And if we said the value of the coin on the exchanges went up 25-50% due to this. That would be of greater benefit than the 50% increase in dividend -- unless the coin price remained stable for like 10 years worth of dividends, perhaps.
Something else to keep in mind... how much do you think people will be getting from this dividend anyway? I mean, actual btc returned, not percentage? Although it's a nice bonus, for those of us who have received dividends from stocks know, it's not exactly a giant windfall. It can takes years to add up to anything really. Increasing the value of the coin on the exchange should be the goal and what will matter most to investors, with the dividends thing being secondary, at least for most I would expect.