...Bad timing from the watch company ?
The Tariff is paid on the wholesale price, not the retail price, so it's effect will be less.
It's been reported that Rolex is requiring their distributors absorb any tariff, which reduces the profit margin, but isn't felt by the consumer. I have no idea if this is true.
The tariffs may not be 31%, but there's a flat 10% (or 15%) that is in effect. Some non-watch companies have begun increasing their costs, rather than continuing to absorb them, which trends towards inflation. Watch manufacturers may not be able to continue to absorb the tariffs.
The effects on the pre-owned market seem to be higher than the new market, at least for now. I read concern from USA buyers of used watches from Japan, as well as Canada and Europe. Not knowing how much a tariff will be has a similar impact of high tariffs, even if not yet implemented. If others are like me, they have stopped thinking of buying pre-owned from Japan.
In response to the OP, yes, it seems to me that the tariffs will reduce watch sales. And raising prices right before the slow down was also bad timing. The high cost of the CHF relative to foreign currencies also has to be affecting Swiss manufacturers, (although it's been said that as little as 40% of Swiss watches are actually made in Switzerland, which reduces the impact of the high CHF).
This will have a snowball effect. The slow down is here, with consumer's holding back on purchases. If manufacturers won't be able to continue absorbing the tariff and eventually raise prices, that will slow the market further. The USA is not going to fully eliminate tariffs for the next three years. Maybe tariffs won't be 39%, but they'll be 15 or at least 10%, plus a 10% loss in purchasing power due to exchange rates. Not to mention higher costs elsewhere in the budget.
But this is one person's opinion, and frankly, the impact to the Swiss watch industry is the last thing that keeps me awake at night.