With merge replication, if the subscriber runs out of identities for a range when inserts occur into it, the subscriber will throw an error on the insert into the table, because it is the publication must grant more identities - and the insert is happening on the subscriber. A better practice would be to make the publisher be the receiver of inserts only, but in some environments or situations, inserts can occur to both the publisher and subscriber, thus many people extend the range.
I am curious how sequences compare to identities here, as I can't find any indication that sequences are limited by merge replication setups like identity fields are.
I believe Aaron Bertrand or another MVP has been really big on sequences and I've been trying to push my organization to use them over identities, but it's a long journey.