Is it possible to create a synonym for a sequence in sql server (2014 and onwards)

You might try doing this:

Create a stored procedure that can be called to get the sequence(s)

CREATE OR ALTER PROCEDURE [dbo].[GetNextValueForSomeSequence]
(
    @numberOfNextValueNeeded INT = NULL
)
AS
BEGIN TRY
   SET NOCOUNT ON;
   SET XACT_ABORT ON;

   WITH Pass0 AS (SELECT 1 AS C UNION ALL SELECT 1) --2 rows
       ,Pass1 AS (SELECT 1 AS C FROM Pass0 AS A, Pass0 AS B)--4 rows
       ,Pass2 AS (SELECT 1 AS C FROM Pass1 AS A, Pass1 AS B)--16 rows
       ,Pass3 AS (SELECT 1 AS C FROM Pass2 AS A, Pass2 AS B)--256 rows
       ,Pass4 AS (SELECT 1 AS C FROM Pass3 AS A, Pass3 AS B)--65536 rows
       ,Pass5 AS (SELECT 1 AS C FROM Pass4 AS A, Pass4 AS B)--4,294,967,296 rows
       --I removed Pass5, since I'm only populating the Numbers table to 10,000
       ,Tally AS (SELECT ROW_NUMBER() OVER(ORDER BY C) AS Number FROM Pass5)
   SELECT NEXT VALUE FOR [dbo].[SomeSequence_Seq] [SeqValue]
         ,T.Number [RowNum]
      INTO [dbo].[#TempSequence]
      FROM Tally T
     WHERE T.Number <= COALESCE(@numberOfNextValueNeeded, 1);

   SELECT [RowNum], [SeqValue]
     FROM [dbo].[#TempSequence]

   DROP TABLE [dbo].[#TempSequence]

END TRY
BEGIN CATCH

   THROW;
END CATCH;
GO

Create a synonym for it

CREATE SYNONYM [SYN].[GetNextValueForSomeSequence] FOR [database].[dbo].[SomeSequence_Seq]

And use it somewhere like this:

CREATE TABLE [dbo].[#TempSequence]
(
   [RowNum] INT
  ,[SeqValue]  INT
);
INSERT INTO [Import].[#TempSequence] ([RowNum], [SeqValue])
EXEC [SYN].[GetNextValueForSomeSequence] 1;

Then use it from the temp table.